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The nonlinear properties of the dust-ion-acoustic waves (DIAWs) are investigated by using the hydrodynamic equations together with the Poisson equation in a collisionless pair ion dense plasma containing positive and negative ions, fraction of stationary charged (positive or negative) dust grains and degenerate electrons. An energy balance-like equation involving a Sagdeev-type pseudo-potential is derived. Finite amplitude solutions are obtained numerically and their characteristics are discussed. The small-but finite-amplitude limit is also considered and an exact analytical solution is obtained. The present studies might be helpful to understand the excitation of nonlinear dust-ion-acoustic solitary waves in a dense plasma such as in superdense astrophysical objects. | Quantum plasmas are an important topic in astrophysics and high pressure laboratory physics for more than 50 years. In addition, many condensed matter systems, including the electron gas in metals, metallic nanoparticles, or electron-hole systems in semiconductors and heterostructures, exhibit—to some extent—plasmalike behavior. Among the key theoretical approaches that have been applied to these systems are quantum kinetic theory, Green function theory, quantum Monte Carlo, semiclassical and quantum molecular dynamics, and more recently, density functional theory simulations. These activities are in close contact with the experiments and have firmly established themselves in the fields of plasma physics, astrophysics, and condensed matter physics. About two decades ago, a second branch of quantum plasma theory emerged that is based on a quantum fluid description and has attracted a substantial number of researchers. The focus of these studies has been on collective oscillations and linear and nonlinear waves in quantum plasmas. Even though these papers pretend to address the same physical systems as the more traditional papers mentioned above, the former appear to form a rather closed community that is largely isolated from the rest of the field. The quantum hydrodynamics (QHD) results have—with a few exceptions—not found application in astrophysics or in experiments in condensed matter physics. Moreover, these results practically did not have any impact on the former quantum plasma theory community. One reason is the unknown accuracy of the QHD for dense plasmas. In this paper, we present a novel derivation, starting from reduced density operators that clearly point to the deficiencies of QHD, and we outline possible improvements. It is also to be noted that some of the QHD results have attracted negative attention being criticized as unphysical. Examples include the prediction of “novel attractive forces” between protons in an equilibrium quantum plasma, the notion of “spinning quantum plasmas,” or the new field of “quantum dusty plasmas.” In the present article, we discuss the latter system in some detail because it is a particularly disturbing case of formal theoretical investigations that are detached from physical reality despite bold and unproven claims of importance for, e.g., dense astrophysical plasmas or microelectronics. We stress that these deficiencies are not a problem of QHD itself, which is a powerful and efficient method, but rather are due to ignorance of its properties and limitations. We analyze the common flaws of these works and come up with suggestions to improve the situation of QHD applications to quantum plasmas.Quantum plasmas are an important topic in astrophysics and high pressure laboratory physics for more than 50 years. In addition, many condensed matter systems, including the electron gas in metals, metallic nanoparticles, or electron-hole systems in semiconductors and heterostructures, exhibit—to some extent—plasmalike behavior. Among the key theoretical approaches that have been applied to these systems are quantum kinetic theory, Green function theory, quantum Monte Carlo, semiclassical and quantum molecular dynamics, and more recently, density functional theory simulations. These activities are in close contact with the experiments and have firmly established themselves in the fields of plasma physics, astrophysics, and condensed matter physics. About two decades ago, a second branch of quantum plasma theory emerged that is based on a quantum fluid description and has attracted a substantial number of researchers. The focus of these studies has been on collective oscillations and linear and nonlinear w... | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,900 |
Čerenkov resonances and the Casimir geometry | Abstract The power spectrum of Cerenkov radiation off a charged particle is calculated in the Casimir geometry defined by two perfectly conducting neutral parallel plates with an isotrpic permeable medium trapped in between. An explicit analytic expression is obtained for the spectrum exhibiting resonances as a function of the geometry. A numerical analysis of the spectrum is also given for water trapped between the plates and the resonant frequencies are calculated. The analysis is given from a quantum mechanical viewpoint. | The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$. | eng_Latn | 10,901 |
Chaotic and turbulent temperature fluctuations in atmospheric free convection | It is shown, using results of direct numerical simulations, laboratory experiments, measurements in the atmospheric boundary layer and satellite infrared radiances data, that the temperature fluctuations in atmospheric free convection can be well described by the distributed chaos approach based on the Bolgiano-Obukhov phenomenology. | We perform a Variational Quantum Monte Carlo simulation of an interacting ::: Fermi gas confined in a three dimensional harmonic potential. This gas is considered as the precursor system from which a molecular bosonic gas is formed. Based in the results of two-body calculations for trapped atoms, we propose a family of variational many-body wave functions that takes into account the qualitative different nature of the BCS and BEC regimes as a function of the scattering length. Energies, densities and correlations functions are calculated and compared with previous results for homogeneous gases. Universality tests at the unitarity limit are also performed. | eng_Latn | 10,902 |
Symmetry of Intramolecular Quantum Dynamics | The main goal of this book is to give a systematic description of intramolecular quantum dynamics on the basis of only the symmetry principles. In this respect, the book has no analogs in the world literature. The obtained models lead to a simple, purely algebraic, scheme of calculation and are rigorous in the sense that their correctness is limited only to the correct choice of symmetry of the internal dynamics. The book is basically intended for scientists working in the field of molecular spectroscopy, quantum and structural chemistry. | Abstract A series of quantization identities are established for static vortex solutions governed by the Born–Infeld type actions. These identities are of a universal nature which are indifferent to the details of the models and provide refined descriptions of divergent energetic quantities. | yue_Hant | 10,903 |
Quantification of propagating and standing surface acoustic waves by stroboscopic X-ray photoemission electron microscopy | The quantification of surface acoustic waves (SAWs) in LiNbO3 piezoelectric crystals by stroboscopic X-ray photoemission electron microscopy (XPEEM), with a temporal smearing below 80 ps and a spatial resolution below 100 nm, is reported. The contrast mechanism is the varying piezoelectric surface potential associated with the SAW phase. Thus, kinetic energy spectra of photoemitted secondary electrons measure directly the SAW electrical amplitude and allow for the quantification of the associated strain. The stroboscopic imaging combined with a deliberate detuning allows resolving and quantifying the respective standing and propagating components of SAWs from a superposition of waves. Furthermore, standing-wave components can also be imaged by low-energy electron microscopy (LEEM). Our method opens the door to studies that quantitatively correlate SAWs excitation with a variety of sample electronic, magnetic and chemical properties. | We study the problem of correspondence between classical and quantum statistical models. We show that (contrary to a rather common opinion) it is possible to construct a natural pre-quantum classical statistical model. The crucial point is that such a pre-quantum classical statistical model is not the conventional classical statistical mechanics on the phase space R2n, but its infinite-dimensional analogue. Here the phase space Ω = H × H, where H is the (real separable) Hilbert space. The classical → quantum correspondence is based on the Taylor expansion of classical physical variables—maps f:Ω → R. The space of classical statistical states consists of Gaussian measures on Ω having zero mean value and dispersion ≈h. The quantum statistical model is obtained as the limh→0 of the classical one. All quantum states including so-called 'pure states' (wavefunctions) are simply Gaussian fluctuations of the 'vacuum field', ω = 0 Ω, having dispersions of the Planck magnitude. | eng_Latn | 10,904 |
Deterministic mode alternation, giant pulses and chaos in a bidirectional CO2 ring laser | Abstract A CO 2 ring laser with a single longitudinal mode propagating in each direction shows a variety of stable, periodic, and aperiodic phenomena depending on gas pressure, cavity detuning and relative excitation. Three distinct low frequency time scales for dynamical behavior are observed and are explained by numerical solutions of an appropriate model. | I discuss a recently unveiled feature in the dynamics of two dimensional coarsening systems on the lattice with Ising symmetry: they first approach a critical percolating state via the growth of a new length scale, and only later enter the usual dynamic scaling regime. The time needed to reach the critical percolating state diverges with the system size. These observations are common to Glauber, Kawasaki, and voter dynamics in pure and weakly disordered systems. An extended version of this account appeared in 2016 C. R. Phys. . I refer to the relevant publications for details. | eng_Latn | 10,905 |
Experimental Demonstration of a Multiphysics Cloak: Manipulating Heat Flux and Electric Current Simultaneously | Invisible cloaks have been widely explored in many different physical systems but usually for a single phenomenon for one device. In this Letter we make an experimental attempt to show a multidisciplinary framework that has the capability to simultaneously respond to two different physical excitations according to predetermined scenarios. As a proof of concept, we implement an electric-thermal bifunctional device that can guide both electric current and heat flux "across" a strong 'scatterer' (air cavity) and restore their original diffusion directions as if nothing exists along the paths, thus rendering dual cloaking effects for objects placed inside the cavity. This bifunctional cloaking performance is also numerically verified for a line-source nonuniform excitation. Our results and the fabrication technique presented here will help broaden the current research scope for multiple disciplines and may pave a way to manipulate multiple flows and create new functional devices, e.g., for on-chip applications. | In this paper we study a degenerate evolution system ::: $\mathbf H_t +\nabla \times [|\nabla \times \mathbf H|^{p-2}\nabla \times \mathbf H]=\mathbf F$ in a bounded domain as well as its limit as $p\to \infty$ subject ::: to appropriate initial and boundary conditions. This system governs the evolution ::: of the magnetic field $\mathbf H$ in a conductive medium under the influence of a system ::: force $\mathbf F$. The system is an approximation of Bean's critical-state model for type-II superconductors. The existence, uniqueness and regularity of solutions to the ::: system are established. Moreover, it is shown that the limit of $\mathbf H(x, t)$ as $p\to \infty$ ::: is a solution to the Bean model. | eng_Latn | 10,906 |
REMARKS ON SOME QUANTUM EFFECTS IN A GLOBAL MONOPOLE SPACE–TIME | We study the behaviour of a nonrelativistic quantum particle interacting with the Kratzer molecular potential in the space–time of a global monopole. We find the energy spectrum and derive the scattering amplitude of massive particles propagating in these fields and show how they differ from their free-space values. | Abstract The aim of the present paper is to give the main characteristics of the finite-source G / M /r queue in equilibrium. Here unit i stays in the source for a random time having general distribution function F i ( x ) with density f i ( x ). The service times of all units are assumed to be identically and exponentially distributed random variables with means 1/μ. It is shown that the solution to this G / M /r model is similar in most important respects to that for the M/M/ r model. | yue_Hant | 10,907 |
Errors in the total Bouguer reduction | This short note discusses various errors in the Bouguer reduction that have been discussed recently in the literature. It also discusses two other errors arising out of the “indirect effect” and the uncertainty in the value of the universal constant of gravitation, G, that previously have not been discussed extensively in the literature. | The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$. | eng_Latn | 10,908 |
A FDM-based Simultaneous Wireless Power and Data Transfer (SWPDT) System Functioning with High-rate Full-duplex Communication | This paper proposes a novel scheme integrating full-duplex data communication into a wireless power transfer system. The power and data are transmitted on the same inductive link comprised of two coreless coils with taps. Frequency division multiplexing (FDM) technique is applied. The power and data are transmitted by using different frequency carriers. The duplexers are designed to implement full-duplex communication. The circuit model of the system is provided to analyze the power and data transfer performance. The crosstalk interference between power and data carriers is discussed. Finally, a prototype has been built to demonstrate the effectiveness of the proposed system. | We present a theoretical framework for equilibrium and nonequilibrium dynamical simulation of quantum states with spin-density-wave (SDW) order. Within a semiclassical adiabatic approximation that retains electron degrees of freedom, we demonstrate that the SDW order parameter obeys a generalized Landau-Lifshitz equation. With the aid of an enhanced kernel polynomial method, our linear-scaling quantum Landau-Lifshitz dynamics (QLLD) method enables dynamical SDW simulations with $N \simeq 10^5$ lattice sites. Our real-space formulation can be used to compute dynamical responses, such as dynamical structure factor, of complex and even inhomogeneous SDW configurations at zero or finite temperatures. Applying the QLLD to study the relaxation of a noncoplanar topological SDW under the excitation of a short pulse, we further demonstrate the crucial role of spatial correlations and fluctuations in the SDW dynamics. | eng_Latn | 10,909 |
FUNDAMENTAL GROUP OF THE DYNAMICAL GRAPH | In this paper we will discuss the dynamical graph and its fundamental group. Also we will study the folding of the dynamical graph and the change of the fundamental group under the folding. The variation of the fundamental group under the variation of time will be discussed. We will study the fundamental group of the simplex and simplicial complex. | We show how to extend the formalism of infinitesimal differential diffusion quantum Monte Carlo to the case of higher derivatives of the ground‐state energy of a molecule with respect to the molecular geometry. We use LiH as an example, but the technique can be extended to more complicated, nonliner molecules as well. We obtain good agreement with experimental values for the energy derivatives and for the harmonic and anharmonic frequencies of LiH and LiD, despite using a compact single‐determinant wave function. | yue_Hant | 10,910 |
Smoluchowski problem for metals with mirror-diffusive boundary conditions | We solve the Smoluchowski problem for the distribution of electron-gas temperatures near the metal surface in the presence of a temperature gradient normal to the surface. We assume mirror-diffusive scattering of electrons by the metal boundary. We develop a special solution method using the Neumann series. | Dynamical properties of hole carriers introduced in the strongly correlated electron systems, i.e. the Mott-Hubbard insulators, are theoretically studied by using both the moment method and the operator transformation method. Particular emphasis is put on effects of the quantum spin fluctuation on the dynamics. | eng_Latn | 10,911 |
Multiple time scale stochastic formulation for collision problems with more than one degree of freedom | Individual molecular collisions have been described by nonequilibrium statistical mechanics in previous work. The present paper deals mainly with refinements and extensions of the theory for systems with more than one internal degree of freedom. For example, it is shown how quantum mechanics for one internal mode can be combined with equations for the other kinds of motion. A multiple time scale stochastic formulation, which allows each degree of freedom its own ’’natural’’ time scale is also described. It is shown, by an application to vibration‐rotation inelasticity in the He4–para‐H2 system, that this method gives results in good agreement with full quantum calculations and experimental measurements. A computationally simple technique for restoring microscopic reversibility to time‐dependent quantum calculations that employ the classical path approximation is also described. | We investigate the OLS-based estimator s2 of the disturbance variance in the standard linear regression model with cross section data when the disturbances are homoskedastic, but spatially correlated. For the most popular model of spatially autoregressive disturbances, we show that s2 can be severely biased in finite samples, but is asymptotically unbiased and consistent for most types of spatial weighting matrices as sample size increases. | eng_Latn | 10,912 |
On the existence of linear trend-free block designs | We present a class of counerexamples for a conjecture on the existence or linear trend free block designs we will also prove a considerably weakened version of this conjecture which will determine all combinations of designs parmetres for which the class of linear trend free block designs is non empty. | We find a general formula for the distribution of time averaged observables for weakly non-ergodic systems. Such type of ergodicity breaking is known to describe certain systems which exhibit anomalous fluctuations, e.g. blinking quantum dots and the sub-diffusive continuous time random walk model. When the fluctuations become normal we recover usual ergodic statistical mechanics. Examples of a particle undergoing fractional dynamics in a binding force field are worked out in detail. We briefly discuss possible physical applications in single particle experiments. | eng_Latn | 10,913 |
The asymmetric resonant exchange qubit under the influence of electrical noise | We investigate the influence of electrical charge noise on a resonant exchange (RX) qubit in a triple quantum dot. This RX qubit is a variation of the exchange-only spin qubit which responds to a narrow-band resonant frequency. Our noise model includes uncorrelated charge noise in each quantum dot giving rise to two independent (noisy) bias parameters $\varepsilon$ and $\Delta$. We calculate the energy splitting of the two qubit states as a function of these two bias detuning parameters to find"sweet spots", where the qubit is least susceptible to noise. Our investigation shows that such sweet spots exist within the low bias regime, in which the bias detuning parameters have the same magnitude as the hopping parameters. The location of the sweet spots in the $(\varepsilon,\Delta)$ plane depends on the hopping strength and asymmetry between the quantum dots. In the regime of weak charge noise, we identify a new favorable operating regime for the RX qubit based on these sweet spots. | Problems associated with the modelling and calculation of quasi-steady-state postfault regimes are considered for abrupt power unbalances. A program permitting calculation of quasi-steady-state postfault regimes with allowance for frequency dynamics and the investigation of their stability is described. Results of calculations based on this program are compared with experiments using an electrodynamic model. It is shown that allowance must be made for frequency dynamics in the analysis of postfault regimes. 9 refs. | eng_Latn | 10,914 |
Sub-Doppler infrared spectroscopy and formation dynamics of triacetylene in a slit supersonic expansion | Infrared spectroscopy and formation dynamics of triacetylene are investigated in a slit jet supersonic discharge and probed with sub-Doppler resolution (≈60 MHz) on the fundamental antisymmetric CH stretch mode (ν5). The triacetylene is generated in the throat of the discharge by sequential attack of ethynyl radical with acetyelene and diacetylene: (i) HCCH → HCC + H, (ii) HCC + HCCH → HCCCCH + H, (iii) HCC + HCCCCH → HCCCCCCH + H, cooled rapidly in the slit expansion to 15 K, and probed by near shot-noise-limited absorption sensitivity with a tunable difference-frequency infrared laser. The combination of jet cooled temperatures (Trot = 15 K) and low spectral congestion permits (i) analysis of rotationally avoided crossings in the ν5 band ascribed to Coriolis interactions, as well as (ii) first detection of ν5 Π–Π hot band progressions built on the ν12 sym CC bend and definitively assigned via state-of-the-art ab initio vibration-rotation interaction parameters (αi), which make for interesting comparison... | In this paper the physical meaning of a nonlinear partial differential equation (nPDE) of the fourth order relating to wave theory is deduced to the first time. The equation under consideration belongs to a class of less studied nPDEs and an explicit physical meaning is not known until now. This paper however bridges the gap between some known results and a concrete application concerning wave theory. We show how one can derive locally supercritical solitary waves as well as locally and nonlocally forced supercritical waves and analytical solutions are given explicitly. ::: ::: Keywords: Nonlinear partial differential equations, evolution equations, supercritical solitary waves, locally supercritical waves, non-locally supercritical waves. | eng_Latn | 10,915 |
A high-temperature thermodynamic investigation of the nb-mo system | The thermodynamic properties of solid Nb(Cb)-Mo alloys have been determined between 1050 and 1300 K using solid state galvanic cells with a thoria-based electrolyte. The activities of niobium and molybdenum exhibit negative deviations from Raoult’s law. The excess entropies of mixing are very small and negative, and the excess integral free energies of mixing are almost equal to the integral enthalpies of mixing. The negative entropies of mixing are attributed to a negative vibrational contribution and/or short-range ordering. | In this paper we study a degenerate evolution system ::: $\mathbf H_t +\nabla \times [|\nabla \times \mathbf H|^{p-2}\nabla \times \mathbf H]=\mathbf F$ in a bounded domain as well as its limit as $p\to \infty$ subject ::: to appropriate initial and boundary conditions. This system governs the evolution ::: of the magnetic field $\mathbf H$ in a conductive medium under the influence of a system ::: force $\mathbf F$. The system is an approximation of Bean's critical-state model for type-II superconductors. The existence, uniqueness and regularity of solutions to the ::: system are established. Moreover, it is shown that the limit of $\mathbf H(x, t)$ as $p\to \infty$ ::: is a solution to the Bean model. | eng_Latn | 10,916 |
N-soliton solutions in the higher-order nonlinear Schroedinger equation | We investigated the possible solutions of the higher order nonlinear Schrodinger (HNLS) equation describing femtosecond optical pulses in an optical fiber system. By using the Hirota direct method, we derived a fundamental solitary wave solution for arbitrary parameters and a N-soliton solution under some conditions. The significance of the soliton solution was discussed. | We discuss the relation between the observed CC, ES, and NC fluxes with the flavor fractional content of the solar neutrino flux seen by SNO. By using existing estimates of the cross sections for the charged and neutral current reactions which take into account the detector resolution, we show how the forthcoming SNO rates unconstrained by the standard $^8$B shape could test the oscillations into active states. We perform a model independent analysis for the Super-K and SNO data, assuming a non distorted spectrum. | eng_Latn | 10,917 |
Strongly nonlinear stationary waves | In this chapter we shall start to investigate wave-plasma interaction processes where the relative density changes produced by the ponderomotive force of the high-frequency field cannot longer be considered as small. Thus, attempts to describe such processes have to start from the fully nonlinear system (3.14)–(3.16). Since there exist no general analytical methods of solving such systems of coupled partial differential equations, progress is usually made by looking for certain special solutions. One method which is often used and gives valuable insight, is that of looking for nonlinear stationary waves. | In this paper, we study a system governed by impulsive semilinear nonautonomous differential equations. We present the β –Ulam stability, β –Hyers–Ulam stability and β –Hyers–Ulam–Rassias stability for the said system on a compact interval and then extended it to an unbounded interval. We use Gronwall type inequality and evolution family as a basic tool for our results. We present an example to demonstrate the application of the main result. | eng_Latn | 10,918 |
Matrix solutions of a noncommutative KP equation and a noncommutative mKP equation | Matrix solutions of a noncommutative KP and a noncommutative mKP equation which can be expressed as quasideterminants are discussed. In particular, we investigate interaction properties of two-soliton solutions. | We introduce a dynamical model of coupled directed percolation systems with two particle species. The two species $A$ and $B$ are coupled asymmetrically in that $A$ particles branch $B$ particles whereas $B$ particles prey on $A$ particles. This model may describe epidemic spreading controlled by reactive immunization agents. We study nonequilibrium phase transitions with focused attention to the multicritical point where both species undergo the absorbing phase transition simultaneously. In one dimension, we find that the inhibitory coupling from $B$ to $A$ is irrelevant and the model belongs to the unidirectionally coupled directed percolation universality class. On the contrary, a mean field analysis predicts that the inhibitory coupling is relevant and a new universality appears with a variable dynamic exponent. Extensive numerical simulations on small-world networks confirm our predictions. | eng_Latn | 10,919 |
Distribution Function of Electron Velocity Perpendicular to the Driving Force in a Uniform Nonequilibrium Steady State | A macroscopically uniform model of a two-dimensional electron system is proposed to study nonequilibrium properties of electrical conduction. By molecular dynamics simulation, the steady state distribution function $P_y$ of electron velocity in a direction perpendicular to an external driving force is calculated. An explicit form of $P_y$ is determined within the accuracy of the numerical simulation, which fits the numerical data well even in the regime where a local equilibrium description is not valid. Although the entire structure of $P_y$ is different from that of a local equilibrium distribution function, the asymptotic structure of the tails of $P_y$ in the limit of large absolute values of the velocity is identical to that of a Maxwell distribution function with a temperature which is different from that in the equilibrium state and the kinetic temperature in the steady state. | Many recent works are devoted to the study of high frequency oscillatory nonlinear waves, and to nonlinear geometric optics. Typical questions are the existence, the propagation, the interaction and the reflection of waves of the form ::: ::: $$ {u^\varepsilon }\left( {t,x} \right) \sim \underline u \left( {t,x} \right) + {\varepsilon ^\alpha }\sum\limits_{n0} {{\varepsilon ^n}} {U_n}\left( {t,x,\varphi \left( {t,x} \right)/\varepsilon } \right). $$ ::: ::: (1.1) | eng_Latn | 10,920 |
Spontaneously appearing diskrete moving kinks in nonlinear acoustic chain with realistic potentials | Molecular dynamic simulations are performed to investigate a long-time evolution of different type initial signals in nonlinear acoustic chains with realistic Exp-6 potential and with power ones. Finite number of long-lifetime kink-shaped excitations is observed in the system in thermodynamic equilibrium. Dynamical equilibrium between the processes of their growth and decay is found. | We consider a stable driven degenerate stochastic differential equation, whose coefficients satisfy a kind of weak H{\"o}rmander condition. Under mild smoothness assumptions we prove the uniqueness of the martingale problem for the associated generator under some dimension constraints. Also, when the driving noise is scalar and tempered, we establish density bounds reflecting the multi-scale behavior of the process. | eng_Latn | 10,921 |
Nonlinear Evolution Equations for Symmetric Beams | The stability of solutions with a prevailing mode in different nonlinear models for beams with intermediate piers is studied. Both linear stability (for bi-modal solutions) and a suitable notion of nonlinear stability are investigated, introducing a proper concept of energy threshold of instability and then determining the optimal placement of the piers, leading to the highest energy threshold. Moreover, it is shown that the nonlinearity which better describes the behavior of actual bridges, among those considered, is the one where the displacement behaves superquadratically and nonlocally. | Measurements performed at the Tevatron of both the like-sign dimuon charge asymmetry inBd;s-meson samples and the mixing-induced CP asymmetry inBs! J= depart from their standard model (SM) predictions. This could be an indication for new CP phases in B = 2 transitions, preferentially in Bs{ Bs mixing. The experimental situation, however, remained inconclusive, as it favored values of the element s of the decay matrix in the Bs-meson system that are notably dierent | yue_Hant | 10,922 |
Collapse of the wave packet without mixture | An explicit model of the quantum measurement process with determinstic dissipative dynamics is presented. The usual results of quantum mechanics are recovered, in complete compatibility with the realistic interpretation. The model exhibits the famous reduction of the wave packet and the occurrence of probability is explained as being due to a random correlation variable whose value is fixed at the very beginning of each of the individual processes. The way that the experimentalist observes the result has no effect on the final state of the system and, consequently, paradoxes like Schrodinger's cat or Wigner's friend are avoided. | Stress vs. strain fluctuations in athermal amorphous solids are an example of `crackling noise' of the type studied extensively in the context of elastic membranes moving through random potentials. Contrary to the latter, we do not have a stochastic equation whose statistics agree with the measured ones. On the other hand we show in this Letter that the statistics of the former exhibit 'density scaling' when the interparticle potential can be well approximated by a power law. The distributions of sizes of dissipative events for a wide range of densities and system sizes follow a single scaling function. We find that both the system-size scaling of energy drops and the entire strain interval statistics are invariant to changes in density. We use this to determine accurately the exponents in the scaling laws, establishing that the present crackling noise belongs to a different universality class. | eng_Latn | 10,923 |
Conductivity in a disordered one-dimensional system of interacting fermions | Dynamical conductivity in a disordered one-dimensional model of interacting fermions is studied numerically at high temperatures and in the weak-interaction regime in order to find a signature of many-body localization and vanishing d.c. transport coefficients. On the contrary, we find in the regime of moderately strong local disorder that the d.c. conductivity sigma0 scales linearly with the interaction strength while being exponentially dependent on the disorder. According to the behavior of the charge stiffness evaluated at the fixed number of particles, the absence of the many-body localization seems related to an increase of the effective localization length with the interaction. | Abstract In this paper, we discuss the existence of the fourth-order boundary value problem { u ( 4 ) = f ( t , u , u ″ ) , 0 t 1 , u ( 0 ) = u ( 1 ) = u ″ ( 0 ) = u ″ ( 1 ) = 0 , where f : [ 0 , 1 ] × R × R → R is continuous, and partly solve the Del Pino and Manasevich's conjecture on the nonresonance condition involving the two-parameter linear eigenvalue problem. We also present a two-parameter nonresonance condition described by circle. | eng_Latn | 10,924 |
Kink-Antikink Collisions in the phi^4 Equation: The n-Bounce Resonance and the Separatrix Map | We provide a detailed mathematical explanation of a phenomenon known as the two-bounce resonance observed in collisions between kink and antikink traveling waves of the $\phi^4$ equations of mathematical physics. This behavior was discovered numerically in the 1980s by Campbell and his collaborators and subsequently discovered in several other equations supporting traveling waves. We first demonstrate the effect with new high-resolution numerical simulations. A pair of kink-like traveling waves may coalesce into a localized bound state or may reflect off each other. In the two-bounce resonance, they first coalesce, but later escape each other's embrace, with a very regular pattern governing the behaviors. Studying a finite-dimensional ``collective coordinates' model, we use geometric phase-plane based reasoning and matched asymptotics toexplain the mechanism underlying the phenomenon, including the origin of several mathematical assumptions needed by previous researchers. We derive a separatrix map for th... | O. Introduction This lecture will unfortunately not be a systematic review of the subject of rigorous results in non-equilibrium statistical mechanics. A preliminary attempt to outline such a review led me quickly to the conclusion that the field is too diverse to be summarized in a single lecture. I have therefore decided instead to discuss a few related.works in depth. The works I have chosen are: 1. The paper of J. Fritz and R. L. Dobrushin[5] on two-dimensional dynamics. 2. The paper of W. Braun and K. Hepp[3] on classical mechanics in the Vlasov limit. 3. A recent preprint by H. van Beijeren, J. L. Lebowitz, H. Spohn, and myself[2] on autocorrelations and fluctuations in the dilute equilibrium hard-sphere gas. | eng_Latn | 10,925 |
Temperature-Dependent Physicochemical Properties and Solvation Thermodynamics of Nitrotoluenes from Solvation Free Energies | Expanded ensemble molecular dynamics simulations are used to calculate the free energies of hydration and self-solvation of low polarity nitrotoluenes over the temperature range of 273 K to 330 K. From this information the liquid, subcooled, and solid-phase vapor pressures, solubilities, Henry’s law constants, hydration and self-solvation entropies, enthalpies, isobaric heat capacities, and enthalpies of vaporization or sublimation are then computed. The values obtained are compared to the limited experimental data available. At a reference temperature of 300 K, the hydration enthalpies are found to be larger in magnitude than hydration entropies for the nitrotoluenes, and vary with the number of nitro groups, while the hydration entropies are almost unchanged as functions of either the number of nitro groups or the solvent accessible surface area. Consequently the variation in the hydration free energies among the nitrotoluenes is due to the variation in their hydration enthalpies. In contrast, both enth... | In this paper the physical meaning of a nonlinear partial differential equation (nPDE) of the fourth order relating to wave theory is deduced to the first time. The equation under consideration belongs to a class of less studied nPDEs and an explicit physical meaning is not known until now. This paper however bridges the gap between some known results and a concrete application concerning wave theory. We show how one can derive locally supercritical solitary waves as well as locally and nonlocally forced supercritical waves and analytical solutions are given explicitly. ::: ::: Keywords: Nonlinear partial differential equations, evolution equations, supercritical solitary waves, locally supercritical waves, non-locally supercritical waves. | eng_Latn | 10,926 |
The Coulomb bridge function and the Pair-distribution functions of the 2-dimensional electron liquid in the quantum regime | The electron-electron pair distribution functions (PDF) of the 2-D electron fluid (2DEF) in the quantum regime (at T=0) are calculated using a classical-map-hyper-netted-chain (CHNC) scheme and compared with currently available Quantum Monte-Carlo (QMC) simulations in the coupling range r_s=1 to 50. We iteratively extract the bridge function of the"equivalent"classical 2-D liquid in the quantum regime. These bridge functions B(r) are relatively insensitive to spin-polarization effects. The structure of the bridge functions changes significantly for r_s>6, suggesting the onset of strongly correlated clusters. The new B(r), appropriate for the long-range Coulomb potential, can be used to replace the hard-sphere B(r) previously used in these calculations. They provide accurate classical representations of the QMC-PDFs even at very strong coupling, and probably at finite-T near T=0. | Abstract In this paper, a simplified congestion control model is considered to study the quasiperiodic motion induced by heterogenous time delays. Analysis for the stability of the equilibrium shows that the Hopf bifurcation curves with diverse frequencies may intersect at the so-called non-resonant double Hopf bifurcation point. Choosing the delays as the bifurcation parameters and employing the method of multiple scales, the amplitude–frequency equations or normal form equations are obtained theoretically. Based on these equations, the dynamics near the bifurcation point is classified. The values of the delays for which the quasiperiodic motion exists can be predicted with an acceptable accuracy. This result provides a reference in designing and optimizing the network systems. | eng_Latn | 10,927 |
Absolute instability in a traveling wave tube model | A model is constructed to evaluate absolute instability which may lead to bandedge oscillations in a traveling wave tube. Under the assumptions (a) that all modes have forward group velocities, and (b) that the slow wave structure has a parabolic dispersion relation in the ω-k plane, the threshold coupling constant (Pierce’s parameter C) is calculated for the onset of absolute instability. The effect of distributed resistive loss in the circuit is included. The axial wave number and the characteristic frequency of the oscillation at the onset are given. | AbstractIn this note we have proved the lifting properties on fibre bundle W under skew product flow π and established that if bounded solutions are positively uniformly stable then a π–invariant subset of W is minimal. | eng_Latn | 10,928 |
Low Noise Synthesized Microwave Local Oscillator for High Capacity Digital Radio Systems using a Dielectric Resonator and a SAW Reference | A novel solution for a synthesized microwave local oscillator suitable for high capacity digital radio systems using multilevel QAM is described. The synthesizer approach covering all radio channels of a given RF band is based on a mechanically and electronically tunable dielectric resonator oscillator phase locked with a wideband PLL to a low noise UHF SAW reference oscillator. Based on a detailed analysis of all noise contributions the PLL configuration is optimized, so that very low phase noise and low sensitivity to microphonics are achieved. | We present a theoretical framework for equilibrium and nonequilibrium dynamical simulation of quantum states with spin-density-wave (SDW) order. Within a semiclassical adiabatic approximation that retains electron degrees of freedom, we demonstrate that the SDW order parameter obeys a generalized Landau-Lifshitz equation. With the aid of an enhanced kernel polynomial method, our linear-scaling quantum Landau-Lifshitz dynamics (QLLD) method enables dynamical SDW simulations with $N \simeq 10^5$ lattice sites. Our real-space formulation can be used to compute dynamical responses, such as dynamical structure factor, of complex and even inhomogeneous SDW configurations at zero or finite temperatures. Applying the QLLD to study the relaxation of a noncoplanar topological SDW under the excitation of a short pulse, we further demonstrate the crucial role of spatial correlations and fluctuations in the SDW dynamics. | eng_Latn | 10,929 |
The application of Bessel discrete variable representation to atomic hydrogen in intense laser fields | The Bessel discrete variable representation (DVR) method is tested to describe the interaction of atomic hydrogen with intense laser fields by numerically solving the time-dependent Schrodinger equation. Using the Bessel functions of the first kind, the singular terms, r-2 or r-1 at the origin, in the kinetic energy operators are analytically solved. As an illustration example, the high-order harmonic generation (HOHG) spectra in atomic hydrogen is calculated in length and acceleration forms. From the numerical results, it is concluded that this simple Bessel DVR may be a useful method for describing the interaction of atomic hydrogen with intense laser fields. | In this paper we study a degenerate evolution system ::: $\mathbf H_t +\nabla \times [|\nabla \times \mathbf H|^{p-2}\nabla \times \mathbf H]=\mathbf F$ in a bounded domain as well as its limit as $p\to \infty$ subject ::: to appropriate initial and boundary conditions. This system governs the evolution ::: of the magnetic field $\mathbf H$ in a conductive medium under the influence of a system ::: force $\mathbf F$. The system is an approximation of Bean's critical-state model for type-II superconductors. The existence, uniqueness and regularity of solutions to the ::: system are established. Moreover, it is shown that the limit of $\mathbf H(x, t)$ as $p\to \infty$ ::: is a solution to the Bean model. | eng_Latn | 10,930 |
Primal-Dual Logarithmic Barrier and Augmented Lagrangian Function to the Loss Minimization in Power Systems | This article presents a new approach to minimize the losses in electrical power systems. This approach considers the application of the primal-dual logarithmic barrier method to voltage magnitude and tap-changing transformer variables, and the other inequality constraints are treated by augmented Lagrangian method. The Lagrangian function aggregates all the constraints. The first-order necessary conditions are reached by Newton's method, and by updating the dual variables and penalty factors. Test results are presented to show the good performance of this approach. | Abstract In this paper, we investigate the time-dependent Ginzburg–Landau (TDGL) equations coming from the superfluid atomic Fermi gases near the Feshbach resonance from the fermion–boson model. By the method of a priori estimates, we get the existence of global attractors in the case of BCS–BEC crossover. | eng_Latn | 10,931 |
Soliton solutions for some x-dependent nonlinear evolution equations | Under investigation in this paper are two x-dependent nonlinear evolution equations: the generalized x-dependent nonlinear Schrodinger (NLS) equation and the modified Korteweg–de Vries (KdV) equation. With the help of Hirota method and symbolic computation, the one- and two-soliton solutions have been obtained for the generalized x-dependent NLS and KdV equations. Propagation and evolution of one soliton have been investigated through the physical quantities of amplitude, width and velocity. The effects of the parameters in the equations on the interaction of two solitons have been studied analytically and graphically. | In this paper, we investigate the applicability of the comonotonicity approach in the context of various benchmark models for equities and commodities. Instead of classical Levy models as in Albrecher et al. we focus on the Heston stochastic volatility model, the constant elasticity of variance (CEV) model and Schwartz’ 1997 stochastic convenience yield model. We show how the technical difficulties of inverting the distribution function of the sum of the comonotonic random vector can be overcome and that the method delivers rather tight upper bounds for the prices of Asian Options in these models, at least for strikes which are not too large. As a by-product the method delivers super-hedging strategies which can be easily implemented. | eng_Latn | 10,932 |
Observation of Algebraic Time Order for Two-Dimensional Dipolar Excitons | Emergence of algebraic quasi-long-range order is a key feature of superfluid phase transitions at two dimensions. For this reduced dimensionality interactions prevent Bose-Einstein condensation with true long range order, at any finite temperature. Here, we report the occurence of algebraic order in a strongly interacting quantum liquid formed by dipolar excitons confined in a bilayer semiconductor heterostructure. We observe a transition from exponential to algebraic decay of the excitons temporal coherence, accompanied by a universal scaling behaviour of the equation of state. Our results provide strong evidence for a Berezinskii-Kosterlitz-Thouless (BKT) transition in a multi-component boson-like system governed by strong dipolar interactions. | This paper considers the search for locally and maximin optimal designs for multi-factor nonlinear models from optimal designs for sub-models of a lower dimension. In particular, sufficient conditions are given so that maximin D-optimal designs for additive multi-factor nonlinear models can be built from maximin D-optimal designs for their sub-models with a single factor. Some examples of application are models involving exponential decay in several variables. | eng_Latn | 10,933 |
On sandwich theorems for multivalent functions involving a generalized differential operator | The purpose of this paper is to derive some subordination and superordination results for multivalent functions involving certain differential operator. | Abstract In this paper, we investigate the time-dependent Ginzburg–Landau (TDGL) equations coming from the superfluid atomic Fermi gases near the Feshbach resonance from the fermion–boson model. By the method of a priori estimates, we get the existence of global attractors in the case of BCS–BEC crossover. | eng_Latn | 10,934 |
Existence of pure strategy Nash equilibrium in Bertrand-Edgeworth oligopolies | Price duopoly and capacity constraints | Nonequilibrium evolution of strong-field anisotropic ionized electrons towards a delayed plasma-state | eng_Latn | 10,935 |
How to derive Schrödinger equation? | How can one derive Schrödinger equation? | How can one derive Schrödinger equation? | eng_Latn | 10,936 |
Improved Soliton Amplitude Estimation via the Continuous Spectrum | In soliton communication systems, the continuous nonlinear spectrum, ideally zero, is conventionally ignored at the receiver. In this paper, we exploit correlation between the received continuous spectrum and perturbations of the discrete soliton eigenvalue. We propose four estimation schemes, classified into two categories, one based on the nonlinear Fourier transform (NFT) and the other based on minimum Euclidean distance. Both categories comprise two schemes, one that exploits the received continuous spectral function to achieve improved estimation and one that does not. Numerical simulations demonstrate that significant reduction in estimation error can be achieved when the continuous spectrum is exploited, translating into improved information transmission rates of up to ${\text{46}}\%$ compared to the reference NFT-based scheme. | The theoretical analysis of the precision and the calculation of finite element of two point difference scheme were presented. It shows that the scheme of Crank Nicolson has highest precision of solutions. However,there is still an effect of the oscillation on the precision of solution especially with longer time step. | eng_Latn | 10,937 |
Linear Recurring Sequences with Cycle Shift Operator over F_4 | This paper presents a new_type linear recurring sequence model over F_4 by adding cycle shift operator to linear recurring sequence over F_4. We first transform study of the model into research on linear recurring sequence over a module. With the aid of matrix representation, we turn it into further study on properties of polynomial matrix of rank 2 over F_2. Nonsingularity of this new linear recurring sequence is discussed in the end. | We present what is to our knowledge the most complete 1-D numerical analysis of the evolution and the propagation ::: dynamics of an ultrashort laser pulse in a Ti:Sapphire laser oscillator. This study confirms the dispersion ::: managed model of mode-locking, and emphasizes the role of the Kerr nonlinearity in generating mode-locked ::: spectra with a smooth and well-behaved spectral phase. A very good agreement with experimental measurements ::: of pulse energy, spectrum, and temporal width of extracavity compressed pulses is found. | eng_Latn | 10,938 |
Acoustic diagnostics of the explosive boiling up of a transparent liquid on an absorbing substrate induced by two nanosecond laser pulses | Photoacoustic pressure signals produced in an absorbing substrate under a layer of a transparent liquid irradiated by two successive nanosecond laser pulses are studied experimentally. The first pulse causes the heating and explosive boiling up of the liquid layer in contact with the irradiated surface, while the second pulse reaches the target at the time when a vapour film has already formed on its surface. The second photoacoustic response contains additional information on heat-and-mass transfer between the liquid and substrate surfaces separated by the vapour film. | In this paper the physical meaning of a nonlinear partial differential equation (nPDE) of the fourth order relating to wave theory is deduced to the first time. The equation under consideration belongs to a class of less studied nPDEs and an explicit physical meaning is not known until now. This paper however bridges the gap between some known results and a concrete application concerning wave theory. We show how one can derive locally supercritical solitary waves as well as locally and nonlocally forced supercritical waves and analytical solutions are given explicitly. ::: ::: Keywords: Nonlinear partial differential equations, evolution equations, supercritical solitary waves, locally supercritical waves, non-locally supercritical waves. | eng_Latn | 10,939 |
Progress in the Asymmetric Additions of Alkylzinc Reagents to Imines | This review covers the recent advances on the asymmetric addition reactions of alkylzinc reagents with imines. 31 References were quoted. | Abstract In this paper we investigate two iterative methods for solving one problem of nonlinear optics. The main goal is not only to find a stationary solution but also to investigate its stability. It is shown that both methods have very different stability properties and the less stable algorithm is close to the approximation of the physically important non-stationary problem. We also propose a new iterative algorithm for solving a more complicated problem which describes the optical conjugation in stimulated Brillouin backscattering with pump depletion. This algorithm is based on a symmetrical splitting scheme and the nonlinear interaction is approximated by using the special mass conservation property of the discrete problem. Thus, we obtain a conservative iterative algorithm. The results of the numerical experiments are presented and they confirm our theoretical conclusions. | eng_Latn | 10,940 |
Analysis and scheme design of highway tunnel back lighting | The paper studies the implementation of back lighting through simulation according to the development of the back lighting technology and existing lighting conditions firstly.The design of the back lighting was completed in the real tunnel.The back lighting scheme for highway tunnel is proposed to solve the glare,strobe and other problems of highway tunnel lighting.Results show that our scheme is significant in the economy and society since it can save energy and enhance the lighting effects by comparing with other cases. | Preface Bose-Einstein Condensation in Nonlinear System New Aspects of Relaxation Processes in Cryogenic Solids Induction Transformer Coupled Discharges: Investigation & Application P-Type InGaAs/AlGaAs Quantum Well Structures for Infrared Photodetection A D-3He Spherical Tokamak Reactor with the Plasma Current Ramp-Up by Vertical Field 5-Dimension Space-Time Field Theory & Realization of Matter Chemical Physics of Phonons & Superconductivity: A Heuristic Approach Description of the Ultraslow Light Phenomenon in Atomic Bose Condensates in the Framework of the Microscopic Approach Energy Decay Mechanism of Quantum Grid Turbulence in He II Below 1 K Dark Matter Haloes as Fruits of Merger Trees in a CDM Garden Application of GEANT4 Code in Gamma Irradiation Processing Stochastic Dynamic Systems with Long-Range Correlations: Basic Notions & Applications Index. | eng_Latn | 10,941 |
Anomalous scaling of fermions and order parameter fluctuations at quantum criticality | We analyze the quantum phase transition between a semimetal and a superfluid in a model of attractively interacting fermions with a linear dispersion. The quantum critical properties of this model cannot be treated by the Hertz-Millis approach since integrating out the fermions leads to a singular Landau-Ginzburg order parameter functional. We therefore derive and solve coupled renormalization group equations for the fermionic degrees of freedom and the bosonic order parameter fluctuations. In two spatial dimensions, fermions and bosons acquire anomalous scaling dimensions at the quantum critical point, associated with non-Fermi liquid behavior and non-Gaussian order parameter fluctuations. | Abstract The theory of normal grain growth that invokes random walk is further extended by allowing for biases in step direction. It is concluded that the predictions of this theory are in overall quantitative accord with experiment. However, the degree of agreement between theory and experiment as to the exact form of the grain size distribution function remains in doubt because of a lack of precision in the definition and measurement of grain size. Possibly, this difficulty may be surmounted by replacing measurements of grain size by those of the lengths of grain boundary edges as found in planar sections of polycrystals. | eng_Latn | 10,942 |
Bounds on codes derived by counting components in Varshamov graphs | We develop methods for estimating the number of components in the Varshamov graph of a linear code and derive some new lower bounds on minimum distance for nonbinary codes. | We perform a Variational Quantum Monte Carlo simulation of an interacting ::: Fermi gas confined in a three dimensional harmonic potential. This gas is considered as the precursor system from which a molecular bosonic gas is formed. Based in the results of two-body calculations for trapped atoms, we propose a family of variational many-body wave functions that takes into account the qualitative different nature of the BCS and BEC regimes as a function of the scattering length. Energies, densities and correlations functions are calculated and compared with previous results for homogeneous gases. Universality tests at the unitarity limit are also performed. | eng_Latn | 10,943 |
Measurement of the Axial-Vector Coupling Constant $g_A$ in Neutron Beta Decay | The matrix element \Vud of the CKM matrix can be determined by two independent measurements in neutron decay: the neutron lifetime $\tau_n$ and the ratio of coupling constants $\lambda=g_A/g_V$, which is most precisely determined by measurements of the beta asymmetry angular correlation coefficient~$A$. We present recent progress on the determination of these coupling constants. | We present an analytical derivation of the distributed model from the experimentally well confirmed lumped approach for the description of light propagation in mode-locked fiber lasers operating in the scalar regime where the dynamics is mainly governed by the propagation of a single field component. As a limiting case of the distributed model we identify the complex cubic-quintic Ginzburg–Landau equation (CQGLE). One important result consists of deriving explicit relations between the coefficients of the distributed models to the realistic laser parameters. We numerically demonstrate that the results obtained by using the general distributed model are in very good agreement with those of the lumped model, whereas results of the CQGLE can significantly deviate for a certain range of parameters. Moreover, we demonstrate that the validity of the CQGLE approach strongly depends on the operation regime of the saturable absorber. | eng_Latn | 10,944 |
The order-disorder transition in colloidal suspensions under shear flow | We study the order?disorder transition in colloidal suspensions under shear flow by performing Brownian dynamics simulations. We characterize the transition in terms of a statistical property of the time-dependent maximum value of the structure factor. We find that its power spectrum exhibits power-law behaviour only in the ordered phase. The power-law exponent is approximately ?2 at frequencies greater than the magnitude of the shear rate, while the power spectrum exhibits 1/f-type fluctuations in the lower frequency regime. | We investigated a Bose system confined in one-dimensional channel by using quantum Monte Carlo simulations. We observed temperature dependences of the superfluid density and two correlation functions along the tubal and the circumferential directions of the channel. As temperature is lowered, first the correlation develops along the circumference, and then it develops along the tubal and the Kosterlitz-Thouless (KT) phase appears at the temperature depending on the confining potential and the ratio of the circumferential length to the length of the channel. We found that the onset temperature of the superfluidity observed by a torsional oscillator measurement depends on the direction of the torsion in this system. | eng_Latn | 10,945 |
Influences of Physical Parameters on Mixed Convection in a Horizontal Lid-Driven Cavity with an Undulating Base Surface | The problem of steady, laminar, and incompressible mixed convection flow in a horizontal lid-driven cavity is studied. In this investigation, two vertical walls of the cavity are perfectly insulated and the wavy bottom wall is considered at an identical temperature higher than the top lid. The enclosure is assumed to be filled with a Bousinessq fluid. The study includes computations for different physical parameters, such as cavity aspect ratio (AR) from 0.5 to 2, amplitude of undulating wall (A) from 0 to 0.075, and number of undulations (λ) from 0 to 3. The pressure-velocity form of Navier-Stokes and energy equations are used to represent the mass, momentum, and energy conservations of the fluid medium in the cavity. The governing equations and boundary conditions are converted to dimensionless form and solved numerically by the penalty finite element method with discretization by triangular mesh elements. Flow and heat transfer characteristics are presented in terms of streamlines, isotherms, average N... | Abstract Applying the self-consistent solitonic approach [1] to the extended Peierls-Hubbard model on odd rings, the interplay of el-el interactions U, V , various off-diagonal interactions, and external dimerization for the dimerization amplitude is studied by exact diagonalizations in the adiabatic limit. The applicability of an effective spin-Peierls Hamiltonian in the intermediate correlation regime U ~ 3t typical for conjugated polymers and an approximate analytical solution based on the Bethe-ansatz solution for the spin velocity and the continuum model solution for the spin-Peierls problem are discussed. | eng_Latn | 10,946 |
Density-dependent synthetic magnetism for ultracold atoms in optical lattices | Raman-assisted hopping can allow for the creation of density-dependent synthetic magnetism for cold neutral gases in optical lattices. We show that the density-dependent fields lead to a non-trivial interplay between density modulations and chirality. This interplay results in a rich physics for atoms in two-leg ladders, characterized by a density-driven Meissner- to vortex-superfluid transition, and a non-trivial dependence of the density imbalance between the legs. Density-dependent fields also lead to intriguing physics in square lattices. In particular, it leads to a density-driven transition between a non-chiral and a chiral superfluid, both characterized by non-trivial charge density-wave amplitude. We finally show how the physics due to the density-dependent fields may be easily probed in experiments by monitoring the expansion of doublons and holes in a Mott insulator, which presents a remarkable dependence on quantum fluctuations. | In order to design an effective control policy for the 10 m diameter primary mirror of the Grantecan Telescope, the coupling among the segments that compose the mirror through the structure that supports it must be treated. We present the mathematical demonstration of two important results in order to deal with the mirror dynamics decoupling. Those are: 1) the multiplicity of the eigenvalue corresponding to the mirror segments decreases as the number of structure modes considered increases, and 2) the vectorial subspace composed of the eigenvectors corresponding to the structure and the segments coupled with it is orthogonal to the one composed of the eigenvectors corresponding to the rest of segments. | eng_Latn | 10,947 |
Wannier states and Bose-Hubbard parameters for 2D optical lattices | We consider the physical implementation of a 2D optical lattice with schemes involving three and four light fields. We illustrate the wide range of geometries available to the 3-beam lattice, and compare the general potential properties of the two lattice schemes. Numerically calculating the band structure we obtain the Wannier states and evaluate the parameters of the Bose–Hubbard models relevant to these lattices. Using these results we demonstrate lattices that realize Bose–Hubbard models with 2, 4, or 6 nearest neighbours, and quantify the extent that these different lattices affect the superfluid to Mott-insulator transition. | In the footsteps of our previous work \cite{RamatonBoschi} we generalize the Stefan-Boltzmann and Wien's displacement laws for the $ \textrm{AdS}_5 \times {\cal S}^5 $ spacetime, the background of the AdS/CFT correspondence foremost realization. Our results take into account the $ \textrm{AdS}_5 \times {\cal S}^5 $ full dimensionality in the electromagnetic field $A^{\mu}$ wave equation, which yields the higher-dimensional blackbody characteristic features suggested in literature. In particular, the total radiated power and the spectral radiancy match the original Stefan-Boltzmann and Wien's displacement laws in the low-energy regime up to available experimental data. | eng_Latn | 10,948 |
A Solution of Equations Describing Explosive Instabilities | We have studied the basic equations, which describe three-wave interaction in a plasma, where collisional effects have to be taken into account. An analytical solution has been found and is compared with computer results. | We identify an eigenvalue associated with a dilute two-species Bose-Einstein condensate as the determiner of condensate stability. It plays the same role as the sign of scattering length in a one-species condensate. We predict that there is a range of interspecies interaction strength in which a sodium-rubidium mixture can be stable in a harmonic trap. {copyright} {ital 1997} {ital The American Physical Society} | eng_Latn | 10,949 |
Charge density wave instabilities driven by multiple umklapp scattering | We show that the concept of umklapp-scattering driven instabilities in one-dimensional systems can be generalized to arbitrary multiple umklapp-scattering processes at commensurate fillings given that the system has sufficiently longer range interactions. To this end we study the fundamental model system, namely, interacting spinless fermions on a one-dimensional lattice, via a density-matrix renormalization-group approach. The instabilities are investigated via a method allowing to calculate the ground-state charge stiffness numerically exactly. The method can be used to determine other ground-state susceptibilities in general. | This paper addresses the problem of channel and propagation delay estimation in asynchronous DS/CDMA systems. We consider the uplink connection in DS/CDMA with long spreading codes. The MIMO stochastic gradient algorithm proposed in [6] is estimating a linear combination of the channel impulse responses and the propagation delays. This estimate suffices for the equalization purposes. The propagation delays are estimated with a simple matching scheme. | eng_Latn | 10,950 |
Topological phases of lattice bosons with a dynamical gauge field | Optical lattices with a complex-valued tunnelling term have become a standard way of studying gauge-field physics with cold atoms. If the complex phase of the tunnelling is made density-dependent, such system features even a self-interacting or dynamical magnetic field. In this paper we study the scenario of a few bosons in either a static or a dynamical gauge field by means of exact diagonalization. The topological structures are identified computing their Chern number. Upon decreasing the atom-atom contact interaction, the effect of the dynamical gauge field is enhanced, giving rise to a phase transition between two topologically non-trivial phases. | Theoretical barograms have been calculated for acoustic-gravity waves ::: generated by underground explosions. Two formulations were used. 1) The ::: thermally modeled gravitating atmosphere is excited by a time varying deformation of the earth's surface. The final deformation is the static ::: surface displacement due to a point pressure source at depth in an elastic ::: half-space. 2) The same atmosphere overlying a multilayered half-space ::: is excited by a point pressure source at depth in the solid medium. | eng_Latn | 10,951 |
Models of Disorder: The Theoretical Physics of Homogeneously Disordered Systems | Preface 1. Cellular disorder 2. Topographical disorder 3. Continuum disorder 4. The observation of disorder 5. Statistical mechanics of substitutional disorder 6. Thermodynamics of topological disorder 7. Macromolecular disorder 8. Excitations on a disordered linear chain 9. Excitations on a disordered lattice 10. Electrons in disordered metals 11. Excitations of a toplogically disordered network 12. Dilute and amorphous magnets 13. Electrons in 'gases' References Index. | We find existence and uniqueness results about solutions of Robin's problem for the general anisotropic hyperbolic heat equation in the case of infinitely differentiable coefficients but irregular distributions data for the internal heatsources and boundary and initial conditions. | eng_Latn | 10,952 |
Charge Oscillations in a Double Quantum Dot in the Coulomb Blockade Regime | The two-electron dynamics in a symmetric double quantum dot placed in a onstant electric field is considered. It is shown that, despite the Coulomb blockade, interdot electron-density oscillations are possible. In these oscillations, a charge equal to the charge of a single electron is periodically transferred from one quantum dot to the other. | In this paper, we consider the second order wave equation discretized in space by summation-by-parts-simultaneous approximation term (SBP-SAT) technique. Special emphasis is placed on the accuracy analysis of the treatment of the Dirichlet boundary condition and of the grid interface condition. The result shows that a boundary or grid interface closure with truncation error $\mathcal{O}(h^p)$ converges of order $p + 2$ if the penalty parameters are chosen carefully. We show that stability does not automatically yield a gain of two orders in convergence rate. The accuracy analysis is verified by numerical experiments. | eng_Latn | 10,953 |
Proton spin-lattice relaxation time in the superconducting intercalation complex Tas2(pyridine)1/2 | Proton NMR in TaS2(pyridine)1/2 shows that pyridine molecules form a rigid lattice with slow molecular motions up to 300 K. The protons' T1 is associated with interactions between the metallic layers and the molecular layers at least above 80 K. An anomalous T1 plateau below 80 K might tentatively be attributed to the occurrence of charge density waves. Below TC a large increase of T-11 has been observed in a single crystal sample. | We present what is to our knowledge the most complete 1-D numerical analysis of the evolution and the propagation ::: dynamics of an ultrashort laser pulse in a Ti:Sapphire laser oscillator. This study confirms the dispersion ::: managed model of mode-locking, and emphasizes the role of the Kerr nonlinearity in generating mode-locked ::: spectra with a smooth and well-behaved spectral phase. A very good agreement with experimental measurements ::: of pulse energy, spectrum, and temporal width of extracavity compressed pulses is found. | eng_Latn | 10,954 |
Hierarchy of periodic orbits and associated energy level clusters in a quantum well in the regime of classical chaos | Abstract We have used resonant tunnelling spectroscopy to investigate the energy level spectrum of a wide 60 nm potential well with a strong magnetic field applied at an angle θ to the normal to the barriers. In this geometry, the current-voltage characteristic I(V) reveal distinct series of resonances which change dramatically with both V and θ. In a classical picture, the electron orbits in the well are strongly chaotic for 15° ≤ θ ≤ 75° and voltages V ≤ 1.2 V. However, we have identified a hierarchy of unstable but periodic orbits whose calculated properties explain the origin and θ-dependence of the resonant structure. We show that the classical motion becomes non-chaotic at high bias voltages and that the changeover to stable orbits is characteriaed by the appearance of widely-spaced resonances in I(V). | Abstract The structures observed in recent missing mass experiments 3 He(p, d)X and p( 3 He, d)X are discussed and shown to agree to a high accuracy with a rotational like scheme M = M 0 + M 1 J ( J +1). An explanation is suggested as to why these structures have not been observed in some other experiments. | eng_Latn | 10,955 |
Time-domain PIC-modeling of suppression of self-modulation in the multiple cavity klystron oscillator with delayed feedback | The results of time-domain PIC-modeling of suppression of self-modulation in a four-cavity klystron oscillator with external delayed feedback are presented. The method is based on using an additional feedback loop with properly chosen delay and phase shift. The application of the method increases the self-modulation threshold beam current. This results in significant increase of the output power and efficiency in comparison with the oscillator with a single feedback. | A simplified treatment is proposed to study quantitatively the lattice dynamics of CsK, CsRb, and RbK alloy systems. The volume effect on the lattice dynamics of the pure constituent is considered, and the phonon dispersion relations of the local and band modes are obtained forthe Rb0.71K0.29, Rb0.3K0.7, Cs0.7K0.3, Cs0.7Rb0.3, and Cs0.3Rb0.7 systems. Then, the x-dependence of the local and band mode frequencies is calculated for the Rb1−xKx, Cs1−xKx and Cs1−xRbx systems. | eng_Latn | 10,956 |
Decoherence and dynamics in continuous 3D-cooled atom interferometry | We study decoherence in continuously cooled atom interferometers by performing Raman-Ramsey fringe measurements in a continuous beam of 3D-sub-Doppler-cooled rubidium atoms. The atom beam is produced by a two-stage cold atom source that is designed to mitigate the decoherence of atomic interference caused by cooling induced fluorescence. The atom beam source produces a collimated beam of over 109 atoms/s that is cooled by polarization gradient cooling to temperatures as low as 14 µK. We infer the potential performance of this atom beam source in a cold-atom gyroscope and use numerical models of motion in 6 degrees of freedom to study the expected performance on dynamic platforms. | Summary In this abstract, we propose a new finite-difference scheme for solving wave equations. This scheme splits the multidimensional system into different directions and solves each direction implicitly. Unlike most splitting methods in the literature which produce numerical anisotropy in diagonal directions, this method gives perfect circular impulse responses and allows lateral velocity variations. In this paper, we prove that the proposed scheme is unconditionally stable. In the numerical examples, we show some impulse response tests and compare them with the results from some high-order explicit finite-difference methods. The new method allows larger time step and requires less memory storage during the reverse time | eng_Latn | 10,957 |
The new solitrary wave solutions of the KdV-Burgers equation | With the help of maple,new explicit solitrary wave solutions of KdV-Burgers equation was obtained by bifunction method and Wu-eliminition method,thus the bifunction method was further complemented. | The matrix formalism previously introduced for the discussion of polymer dynamics is rendered more tractable by the introduction of an explicit operator representation satisfying boson commutation rules. Techniques are devised by which singular functions of segment coordinates may be expanded in a fluctuation series (containing ordered products of boson operators) around an equilibrium or nonequilibrium average. The techniques are here applied to equilibrium excluded‐volume expansions, and are shown to give good results. The detailed numerical results are presented in the following paper. The Gaussian potential is adopted for polymer chains in a theta solvent, but methods for its improvement are considered. | eng_Latn | 10,958 |
Some non-Fourier heat conduction characters under pulsed inlet conditions | Through simulating one- and two-dimensional non-Fourier heat conduction problems under different pulsed inlet conditions, this paper numerically predicts some different non-Fourier heat conduction characters arose from different pulse types and different pulse frequencies. Meanwhile, the differences among thermal wave, non-Fourier and Fourier heat conduction are also showed. | Dynamical properties of hole carriers introduced in the strongly correlated electron systems, i.e. the Mott-Hubbard insulators, are theoretically studied by using both the moment method and the operator transformation method. Particular emphasis is put on effects of the quantum spin fluctuation on the dynamics. | eng_Latn | 10,959 |
Statistics of resonances and delay times in random media : beyond random matrix theory | We review recent developments in quantum scattering from mesoscopic systems. Various spatial geometries whose closed analogues show diffusive, localized or critical behaviour are considered. These are the features that cannot be described by the universal random matrix theory results. Instead, one has to go beyond this approximation and incorporate them in a non-perturbative way. Here, we pay particular attention to the traces of these non-universal characteristics, in the distribution of the Wigner delay times and resonance widths. The former quantity captures time-dependent aspects of quantum scattering while the latter is associated with the poles of the scattering matrix. | We studied coupling of the terahertz radiation to periodically structured metal arrays. The role of polarization, surface plasmon dispersion and attenuation are evaluated experimentally and modeled theoretically. | eng_Latn | 10,960 |
A classical model of the photon echo | An observation and the theory of a nonlinear response in the ensemble of nonlinear classical oscillators excited by two field pulses — similar to the phenomenon of a photon echo in optics — are reported. It has been shown that an echo arises in any ensemble with an inhomogeneously broadened line regardless of the type of interaction with a field (classical or quantum). New peculiarities appear during the determinate distribution of frequencies in the ensemble. On the one hand, an echo pulse is observed with a relatively small (about 100) number of oscillatorsN, on the other, new pulses spaced at a distance that is proportional toN arise in the nonlinear response. | We review the current understanding of the acoustic phonon contribution to thermal transport in nanostructures from nanoparticles to thin films and membranes. Confinement and cavity effects will be discussed as well as electrical and optical measurement methods. | eng_Latn | 10,961 |
Well-posedness in the energy space for semilinear wave equations with critical growth | A sensing circuit is provided that is exceptionally sensitive. The circuit can respond to a minute change in a signal to actuate an electrically-operated device. The circuit is relatively simple, uses inexpensive components, and is compact. | This is a status report about the ongoing work on the realization of quantum field theory on curved graphene spacetimes that uses Weyl symmetry. The programme is actively pursued from many different perspectives. Here we point to what has been done, and to what needs to be done. | eng_Latn | 10,962 |
Bose Hubbard Model Confined in the Restricted Geometry | We investigated a Bose system confined in one-dimensional channel by using quantum Monte Carlo simulations. We observed temperature dependences of the superfluid density and two correlation functions along the tubal and the circumferential directions of the channel. As temperature is lowered, first the correlation develops along the circumference, and then it develops along the tubal and the Kosterlitz-Thouless (KT) phase appears at the temperature depending on the confining potential and the ratio of the circumferential length to the length of the channel. We found that the onset temperature of the superfluidity observed by a torsional oscillator measurement depends on the direction of the torsion in this system. | Abstract Reducing the specimen-probe spacing to increase the sensitivity of measurement of weak remanence in geological samples, etc. introduces potential inaccuracies. These are analysed by comparing the field distributions derived for transversely magnetized cylinders with those for dipoles and for nulling coils. An optimum coil geometry is found. | eng_Latn | 10,963 |
Semiclassical dynamics of spin density waves | We present a theoretical framework for equilibrium and nonequilibrium dynamical simulation of quantum states with spin-density-wave (SDW) order. Within a semiclassical adiabatic approximation that retains electron degrees of freedom, we demonstrate that the SDW order parameter obeys a generalized Landau-Lifshitz equation. With the aid of an enhanced kernel polynomial method, our linear-scaling quantum Landau-Lifshitz dynamics (QLLD) method enables dynamical SDW simulations with $N \simeq 10^5$ lattice sites. Our real-space formulation can be used to compute dynamical responses, such as dynamical structure factor, of complex and even inhomogeneous SDW configurations at zero or finite temperatures. Applying the QLLD to study the relaxation of a noncoplanar topological SDW under the excitation of a short pulse, we further demonstrate the crucial role of spatial correlations and fluctuations in the SDW dynamics. | Thank you very much for reading selected works dynamical theory and quantum and classical statistical mechanics. As you may know, people have search numerous times for their chosen books like this selected works dynamical theory and quantum and classical statistical mechanics, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some harmful bugs inside their computer. | eng_Latn | 10,964 |
On partial differential equations of mixed type in N independent variables | It is proved that a large class of 2-nd order linear partial differential equations of mixed type in n independent variables can be solved by using the theory of positive symmetric systems of 1-st order partial differential equations. Some quasilinear equations of mixed type can be treated in the same way. | We study the photoinduced charge separation processes in solution through a pump–probe spectroscopy theory [Dah-Yen Yang and Sheh-Yi Sheu, J. Chem. Phys. 106, 9427 (1997)] numerically. We investigate the detailed mechanism of nonadiabatic transition processes via the transition differential flux analysis. For the harmonic potential surfaces, an electronic coherence motion is observed in the overdamped exothermic activationless and inverted regimes. | eng_Latn | 10,965 |
Superfluid model of high temperature superconductivity | Abstract A model of the superfluid type for high temperature superconductivity is suggested. Critical temperature and critical current density at the T =0 are calculated as functions of the current carriers density. | For Pt. IV see ibid., vol. 3, no. 6, p. 726 (1970). It is shown that the one-component virtual-mode theory of the previous paper, which is a well-defined translationally invariant many-body optical theory of the molecular fluid, can be extended without difficulty to the two-component fluid. It is inferred that the theory of both 'virtual' and 'real' electromagnetic modes developed previously is applicable to fluids with any number of components. | eng_Latn | 10,966 |
Frequency gaps for folded acoustic phonons in superlattices | Abstract We report on calculations of frequency gaps for mixed folded LA and TA phonons propagating perpendicular to the layers in a superlattice. We show that for certain growth directions (e.g., [011] and [012]), mini-gaps appear not only at the Brillouin-zone center and boundary, but also in the interior. Results are obtained for GaAsAlAs superlattices. | The authors construct periodic interpolating wavelets and their duals from a periodio ftmction g(x) whose Fourier coefficiente are positive. The corresponding decomposition and reconstructlon algorithm is also given. The spline example shows that such kind of wavelets shares good localization with any desired regularity and symmetry. The constructlon dependsessentially on the finite Fourier Transformation and the theory of circulant matrix. | eng_Latn | 10,967 |
Volume, pressure and temperature dependences of vibrational frequencies | Abstract The mode vibrational frequencies of crystals depend solely on the variation of volume. The way frequencies change with temperature and pressure is purely a result of volume changes with temperature and pressure. This conclusion appears to be substantiated by the experimental results of forsterite. | We perform a Variational Quantum Monte Carlo simulation of an interacting ::: Fermi gas confined in a three dimensional harmonic potential. This gas is considered as the precursor system from which a molecular bosonic gas is formed. Based in the results of two-body calculations for trapped atoms, we propose a family of variational many-body wave functions that takes into account the qualitative different nature of the BCS and BEC regimes as a function of the scattering length. Energies, densities and correlations functions are calculated and compared with previous results for homogeneous gases. Universality tests at the unitarity limit are also performed. | eng_Latn | 10,968 |
Selective reduction of sulfuric chloride: the structure of the chlorosulfite ion | The stable salt 2 is obtained from the reaction of SO2Cl2 with the imidazol-2-ylidene 1; the pyramidal structure of the chlorosulfite anion is confirmed both by X-ray structure and MO calculation. | We investigated the possible solutions of the higher order nonlinear Schrodinger (HNLS) equation describing femtosecond optical pulses in an optical fiber system. By using the Hirota direct method, we derived a fundamental solitary wave solution for arbitrary parameters and a N-soliton solution under some conditions. The significance of the soliton solution was discussed. | eng_Latn | 10,969 |
Driven lattice gases : new perspectives | We report analytical studies of a series of driven systems: the driven lattice gas model, the randomly driven lattice gas, the two-temperature model and the driven bi-layer lattice gas. All of them are described within a unified framework that preserves the dynamical specifications present at the discrete level. Thus, we provide a set of Langevin equations for these driven systems that illustrate how some microscopic details can affect the macroscopic properties. | The objective of the article is to present several original results, obtained through the combined approach of experiments and two-dimensional modeling, which could suggest solutions in order to improve the choice of the operating conditions in an LPCVD (low-pressure chemical vapor deposition) reactor for this kind of deposition | yue_Hant | 10,970 |
Topological susceptibility and instanton size distribution from over-improved cooling | We measure the topological susceptibility by cooling with an over-improved action. In contrast with usual cooling, large instantons survive over-improved cooling indefinitely . By varying the parameter of the over-improved cooling action, we measure the instanton size distribution. | In this paper, we consider the second order wave equation discretized in space by summation-by-parts-simultaneous approximation term (SBP-SAT) technique. Special emphasis is placed on the accuracy analysis of the treatment of the Dirichlet boundary condition and of the grid interface condition. The result shows that a boundary or grid interface closure with truncation error $\mathcal{O}(h^p)$ converges of order $p + 2$ if the penalty parameters are chosen carefully. We show that stability does not automatically yield a gain of two orders in convergence rate. The accuracy analysis is verified by numerical experiments. | eng_Latn | 10,971 |
Particle-in-cell simulations of hot electron generation using defocused laser light in cone targets | The effects of defocusing a high intensity pulse of laser light on the generation of hot electrons in a cone are investigated using particle-in-cell simulations. The results indicate that defocused laser light can soften the electron energy spectrum and increase the coupling efficiency compared to the use of a laser in tight focus. It is shown that this is a consequence of the density profile of plasma produced by the laser prepulse, which is less dense in the case of the defocused laser. The relevance of this result to fast ignition inertial confinement fusion is discussed. | We show that the negative of the number of {ital floppy modes} behaves as a {ital free energy} for both connectivity and rigidity percolation, and we illustrate this result using Bethe lattices. The rigidity transition on Bethe lattices is found to be first order at a bond concentration close to that predicted by Maxwell constraint counting. We calculate the probability of a bond being on the infinite cluster and also on the overconstrained part of the infinite cluster, and show how a {ital specific heat }can be defined as the second derivative of the free energy. We demonstrate that the Bethe lattice solution is equivalent to that of the random bond model, where points are joined randomly (with equal probability at all length scales) to have a given coordination, and then subsequently bonds are randomly removed. {copyright} {ital 1999} {ital The American Physical Society} | eng_Latn | 10,972 |
Physicists Discover Way to “Switch” Between the Different States of Matter | An international team of physicists has managed for the first time to experimentally observe a transition between two different states of matter: a propagating polariton-soliton and a Bose-Einstein condensate. Furthermore, the researchers developed a theoretical model to explain such transitions and found a way to “switch” between the different states by changing the laser pumping power in the polariton formation process. The results are published in Physical Review Letters.
Nonlinear systems are extensively studied in a wide range of physical systems, notably in photonics. In such systems, interactions between particles lead to a whole range of novel effects such as nonlinear transitions between different basic states of matter including polaritons, solitons and Bose-Einstein condensates.
“Polaritons are quasiparticles formed due to the hybridization of matter and light. Once they are supplied with additional energy and densities, they form collective excitations, solitons. A soliton has an ability to propagate in space while preserving its shape. In other words, despite being a collective state consisting of many particles, a soliton behaves like a single particle. At the same time, a Bose-Einstein condensate is a quantum state of matter where all particles, in our case polaritons, populate the ground state of the system with minimal energy. Usually, the ground state is extended through the entire area of the system under study. The soliton and Bose-Einstein condensate are two widely different regimes, and we managed to observe the transition between them,” explains Ivan Shelykh, head of the International Laboratory of Photoprocesses in Mesoscopic Systems at ITMO University in St Petersburg.
The group, which included Professor Maurice Skolnick, Dr. Dmitry Krizhanovskii and Dr. Maksym Sich from the University of Sheffield, obtained the experimental data, while the theoretical group, led by Ivan Shelykh, developed a theoretical model for quantitative description of the experiment.
“First we had to create polaritons,” says Maurice Skolnick. “This required a fabrication of initial semiconductor structures with precisely defined features. Next, we shone a laser on the structure at temperatures as low as 4 degrees Kelvin, creating polaritons and then detecting the light that they emit.”
The researchers observed that an increase in the laser pumping power triggered nonlinear effects in the system.
“By increasing the laser strength, we create more and more particles, which begin to interact with each other. Therefore, the whole system goes into a nonlinear regime. Separate polaritons form solitons, which then transition into a Bose-Einstein condensate. Although it was clear we had obtained some interesting results, without a good theory we would have never understood what they actually meant,” Skolnick continues.
The theoretical model explaining the experimental data was developed by Ivan Shelykh’s group. This collaborative research project was carried out under a grant of the Ministry of Education and Science of the Russian Federation on the study of hybrid light states.
“The ‘megagrant’ gave us the ability to initiate a productive collaboration with leading experimental scientists from Sheffield. During a year of our collaborative work we published two major papers that combined experimental and theoretical science,” Shelykh notes.
Further research plans include decreasing the size of nonlinear transitions systems to the subwavelength scale. Maurice Skolnick described the project’s perspectives:
“As of now, this study has a mainly fundamental significance, as we have described a completely new aspect of physics. Yet once we produce miniature devices, it will be possible to use nonlinear transitions between different states of matter for telecommunications or, for example, for the creation of new lasers.”
Publication: M. Sich, et al., “Transition from Propagating Polariton Solitons to a Standing Wave Condensate Induced by Interactions,” Physical Review Letters, 2018; doi:10.1103/PhysRevLett.120.167402 | ×
LOFT - A SALAAM MALE GENIE (Chants beat chop)
coucou chloe - doom
Bored Lord - Devil Talkin’
Ca$h Bandicoot - Bells
Superfície - Cerol
JAVASCRIPT - P!nky Ring
Randomer - Juju
Chants - Crushed Lollipop (VIP)
SHALT x Sean Paul - Temperature (MICHAELBRAILEY ‘Archeron’ ULTIMATE DESTRUCTION EDIT)
NKC - No Drama
NOIRE - TWO FUQS
Air Max ‘97 x Sia - HPE Heart
TSVI - Assam’s Children
Tim Hecker - No Drums
Superfície - Febre Do Vale
David Bowie - I Can’t Give Everything Away (Farewell mix)
w. baer - what’s to come
Chants - Crushed Lollipop (SHALT remix)
CYPHR - Stretch Reflex
Chants - Susurrus pt. II (Sim Hutchins remix)
GRRL x Mariah - We Belong Together (MICHAELBRAILEY ‘Workout’ RUNAWAY GYM Edit)
Balasa - Teri Duniya (Drum mix)
Mumdance & Logos - Drum Boss (Jawside edit)
Ophex - Trailer Home
Lil Crack - Tactical Violence
Bonaventure - Riposte
Scientist - Plague of the Zombies
It's been a little over a year since Wisconsin producer released his tactile, expressive LP We Are All Underwater , and he's got some new material on the horizon. He'll release a new EP on Los Angeles' Astral Plane Recordings this month, and in the run up to it he's been sharing some extras, including a dizzying DJ set for London's popular NTS Radio and an EP featuring remixes from SHALT, Liquid City Motors and Sim Hutchins.You can stream both below, but first here's the tracklist for his 50-minute DJ set. It's fast and wide-ranging; you can get some serious housework done to this thing: | eng_Latn | 10,973 |
What can be fully converted into work in a reversible isothermal expansion of an ideal gas? | For "closed systems" with no external source or sink of energy, the first law of thermodynamics states that a system's energy is constant unless energy is transferred in or out by mechanical work or heat, and that no energy is lost in transfer. This means that it is impossible to create or destroy energy. While heat can always be fully converted into work in a reversible isothermal expansion of an ideal gas, for cyclic processes of practical interest in heat engines the second law of thermodynamics states that the system doing work always loses some energy as waste heat. This creates a limit to the amount of heat energy that can do work in a cyclic process, a limit called the available energy. Mechanical and other forms of energy can be transformed in the other direction into thermal energy without such limitations. The total energy of a system can be calculated by adding up all forms of energy in the system. | Likewise, group theory helps predict the changes in physical properties that occur when a material undergoes a phase transition, for example, from a cubic to a tetrahedral crystalline form. An example is ferroelectric materials, where the change from a paraelectric to a ferroelectric state occurs at the Curie temperature and is related to a change from the high-symmetry paraelectric state to the lower symmetry ferroelectic state, accompanied by a so-called soft phonon mode, a vibrational lattice mode that goes to zero frequency at the transition. | eng_Latn | 10,974 |
Universal Hall Response in Synthetic Dimensions | We theoretically study the Hall effect on interacting $M$-leg ladder systems, comparing different measures and properties of the zero temperature Hall response in the limit of weak magnetic fields. Focusing on $SU(M)$ symmetric interacting bosons and fermions, as relevant for e.g. typical synthetic dimensional quantum gas experiments, we identify an extensive regime in which the Hall imbalance $\Delta_{\rm H}$ is universal and corresponds to a classical Hall resistivity $R_{\rm H}=-1/n$ for a large class of quantum phases. Away from this high symmetry point we observe interaction driven phenomena such as sign reversal and divergence of the Hall response. | We prove existence of solutions for a class of systems of subelliptic PDEs arising from Mean Field Game systems with H\"ormander diffusion. These results are motivated by the feedback synthesis Mean Field Game solutions and the Nash equilibria of a large class of $N$-player differential games. | eng_Latn | 10,975 |
Infinitely many solutions for a class of superlinear Dirac–Poisson system | Abstract This paper is concerned with the nonlinear Dirac–Poisson system − i ∑ k = 1 3 α k ∂ k u + ( V ( x ) + a ) β u + ω u − ϕ u = F u ( x , u ) , − Δ ϕ = 4 π | u | 2 , in R 3 where V is an external potential and F is a superlinear nonlinearity modeling various types of interactions. Existence and multiplicity of stationary solutions are obtained for the system with periodicity condition via variational methods. | The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$. | eng_Latn | 10,976 |
Overtone resonance enhanced single-tube on-beam quartz enhanced photoacoustic spectrophone | A single-tube on-beam quartz enhanced photoacoustic spectroscopy (SO-QEPAS) spectrophone, which employs a custom-made quartz tuning fork (QTF) having a prong spacing of 700 μm and operating at the 1st overtone flexural mode, is reported. The design of QTF prong geometry allows the bare QTF to possess twice higher Q-factor values for the 1st overtone resonance mode falling at ∼17.7 kHz than in the fundamental resonance mode at ∼2.8 kHz, resulting in an 8 times higher QEPAS signal amplitude when operating in the 1st overtone resonance mode. Both the vertical position and length of the single-tube acoustic micro-resonator (AmR) were optimized to attain optimal spectrophone performance. Benefiting from the high overtone resonance frequency and the quasi 1st harmonic acoustic standing waves generated in the SO-QEPAS configuration, the AmR length is reduced to 14.5 mm. This allows the realization of compact spectrophone and facilitates the laser beam alignment through the QTF + AmR system. The signal enhancemen... | In this paper the physical meaning of a nonlinear partial differential equation (nPDE) of the fourth order relating to wave theory is deduced to the first time. The equation under consideration belongs to a class of less studied nPDEs and an explicit physical meaning is not known until now. This paper however bridges the gap between some known results and a concrete application concerning wave theory. We show how one can derive locally supercritical solitary waves as well as locally and nonlocally forced supercritical waves and analytical solutions are given explicitly. ::: ::: Keywords: Nonlinear partial differential equations, evolution equations, supercritical solitary waves, locally supercritical waves, non-locally supercritical waves. | eng_Latn | 10,977 |
Finite groups of global breadth four in the sense of Frobenius | ABSTRACTLet G be a finite group and e a positive integer dividing |G|, the order of G. The size of the set Le(G)={x∈G|xe=1} was studied originally by G. Frobenius, in order to find restrictions on the structure of G. Heineken and Russo [4] introduced B(G)=max{|Le(G)|e|e∈Div(exp(G))} as global breadth in the sense of Frobenius. In this paper, we investigate the groups G with B(G) = 4. | Abstract In this paper, we investigate the time-dependent Ginzburg–Landau (TDGL) equations coming from the superfluid atomic Fermi gases near the Feshbach resonance from the fermion–boson model. By the method of a priori estimates, we get the existence of global attractors in the case of BCS–BEC crossover. | eng_Latn | 10,978 |
On a high-order iterative scheme for a nonlinear love equation | In this paper, a high order iterative scheme is established in order to get a convergent sequence, at a rate of order N, to a local unique weak solution of a nonlinear wave equation associated with homogeneous Dirichlet boundary conditions. This scheme shows that the convergence can be obtained with a high rate if the nonlinear term in the original equation is smooth enough. | Previously developed ``stochastic representation of deterministic interactions`` enables exact treatment of an open system without leaving its native phase space (Hilbert space) due to peculiar stochastic extension of the Liouville (von Neumann) equation for its statistical operator. Can one reformulate the theory in terms of stochastic ``Langevin equations'' for its variables? Here it is shown that in case of classical Hamiltonian underlying dynamics the answer is principally positive, and general explicit method of constructing such equations is described. | eng_Latn | 10,979 |
Schrödinger operators with sparse potentials: asymptotics of the Fourier transform of the spectral measure | Abstract: We study the pointwise behavior of the Fourier transform of the spectral measure for discrete one-dimensional Schrödinger operators with sparse potentials. We find a resonance structure which admits a physical interpretation in terms of a simple quasiclassical model. We also present an improved version of known results on the spectrum of such operators. | In this article we exhibit some balls lying in the quasi-Fuchsian space of once punctured tori, which are maximal in the class of balls with the same centers. The centers of our maximal balls lie on the slice determined by the trace equation y = ¯ x. | eng_Latn | 10,980 |
Stochastic quantization and axial gauges | The simplest form of the Langevin equation for axial-gauge non-Abelian gauge theory fails to reproduce correctly a Wilson-loop calculation. | For a quantum channel of additive Gaussian noise with loss, in the general case of $n$ copies input, we show that up to first order perturbation, any non-Gaussian perturbation to the product thermal state input has a less quantum information transmission rate when the input energy tend to infinitive. | eng_Latn | 10,981 |
Quantum limit for two-dimensional resolution of two incoherent optical point sources | We obtain the multiple-parameter quantum Cram\'er-Rao bound for estimating the transverse Cartesian components of the centroid and separation of two incoherent optical point sources using an imaging system with finite spatial bandwidth. Under quite general and realistic assumptions on the point-spread function of the imaging system, and for weak source strengths, we show that the Cram\'er-Rao bounds for the $x$ and $y$ components of the separation are independent of the values of those components, which may be well below the conventional Rayleigh resolution limit. We also propose two linear optics-based measurement methods that approach the quantum bound for the estimation of the Cartesian components of the separation once the centroid has been located. One of the methods is an interferometric scheme that approaches the quantum bound for sub-Rayleigh separations. The other method using fiber coupling can in principle attain the bound regardless of the distance between the two sources. | The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$. | eng_Latn | 10,982 |
One-dimensional massless Dirac-particles in waveguide arrays with alternating coupling | We experimentally realized a waveguide device with alternating positive and negative coupling and show that this geometry is an optical simulator of the conditions found for a massless relativistic particle described by the one-dimensional Dirac-equations. | By calculating gradient trajectories in direction of ascending and descending scalar gradients a local maximum and a local minimum point is reached. Dissipation elements may then be defined as the spatial region from which the same pair of maximum and minimum points in a scalar field is reached. By exploring the two-point correlation of the scalar gradient along such trajectories it was found that for large elements the mean velocity increment scales linearly with the arclength distance along the trajectory. This is different from the classical Kolmogorov scaling and has consequences for the modeling of the length distribution of dissipation elements. | eng_Latn | 10,983 |
Quantification of Mixed-State Entanglement in a Quantum System Interacting with Two Time-Dependent Lasers | We give a theoretical description of two time-dependent laser beams in the Λ scheme using a unitary transformation method and a trapped three-level ion. We extend earlier investigations aimed at finding the three types of density matrices. We present figures showing that the entanglement degree accelerates due to the time-dependent interaction and the second-order terms of the Lamb–Dicke parameter η(t). Our results explain that the time-dependent ionic–phononic quantum system is observed at a higher degree of entanglement for three optimum times; these are, respectively, 16.5, 110, and 220 fs. These optimum entangled states can be modified for the structure of black holes in a probabilistic Universe. | In this article we are discussing the nature and mechanism of the huge ::: amount of heat generation in Megawatts Energy Catalyzers (E-cat) of Andrea ::: Rossi that are able to change the energetics of our civilization in general. ::: These processes are new effects of Unitary Quantum Theory and do not relate to ::: either chemical or nuclear reactions or phase transfer. | eng_Latn | 10,984 |
Strong optical scattering by femtosecond laser induced microbubbles inside water and other microscopic observations / Sayed Ahmed Islam Sanny | Nonlinear interactions of focused femtosecond laser with water can provide interesting optical phenomena, most commonly, laser induced breakdown in water which creates plasma, self-focusing or filamentation because of loose geometrical focusing condition, white light generation and blue shifted by plasma, conical emission and associated spectra, as well as creation of optical cavitation bubbles and their motions inside water. However, in our work, in addition to the well-known phenomena we have observed a new kind of colorful optical scattering flash from femtosecond laser induced microbubble surface. A closer look under the microscopic observation of the focused region of femtosecond laser pulse leads us to observe this scattering. Additionally, in this work, we also have discussed the nonlinear optical process including our new finding phenomena to elucidate the underlying physical mechanisms and laser induced bubble mechanism from the micro level observational point of view. | A systematic analytic treatment of static and dynamic fluctuations of the interface in the quantized Laplacian growth is given. The quantization procedure implies that the area of the domain equals an integer multiple of the area quanta $\hbar$, which also serves as a short distance cutoff preventing the cusps production in a finite time. The interface dynamics becomes chaotic, because of tiny inevitable fluctuations on a microscale. By using the universal Dyson's Brownian motion to model the time evolution of fluctuations, the Laplacian growth is mapped to the one-dimensional quantum hydrodynamical problem, described by the complex viscous Burgers equation with a viscosity coefficient proportional to the cutoff. Because of the intrinsic instability of the interface dynamics, tiny fluctuations of the interface on a microscale are shown to generate universal patterns with well developed fjords and fingers in a long time asymptotic. | eng_Latn | 10,985 |
Fourier continuation method for incompressible fluids with boundaries | We present a Fourier Continuation-based parallel pseudospectral method for incompressible fluids in cuboid non-periodic domains. The method produces dispersionless and dissipationless derivatives with fast spectral convergence inside the domain, and with very high order convergence at the boundaries. Incompressibility is imposed by solving a Poisson equation for the pressure. Being Fourier-based, the method allows for fast computation of spectral transforms. It is compatible with uniform grids (although refined or nested meshes can also be implemented), which in turn allows for explicit time integration at sufficiently high Reynolds numbers. Using a new parallel code named SPECTER we illustrate the method with two problems: channel flow, and plane Rayleigh-Benard convection under the Boussinesq approximation. In both cases the method yields results compatible with previous studies using other high-order numerical methods, with mild requirements on the time step for stability. | We perform a Variational Quantum Monte Carlo simulation of an interacting ::: Fermi gas confined in a three dimensional harmonic potential. This gas is considered as the precursor system from which a molecular bosonic gas is formed. Based in the results of two-body calculations for trapped atoms, we propose a family of variational many-body wave functions that takes into account the qualitative different nature of the BCS and BEC regimes as a function of the scattering length. Energies, densities and correlations functions are calculated and compared with previous results for homogeneous gases. Universality tests at the unitarity limit are also performed. | eng_Latn | 10,986 |
FOUR-DIMENSIONAL YANG-MILLS THEORY IN LOCAL GAUGE INVARIANT VARIABLES | The general method that allows to formulate 4-D SU(N) Yang-Mills theory in terms of only local gauge invariant variables is presented. For the case N=2, that is discussed in details, this gauge invariant formulation appears to be very similar to R2-gravity. | Abstract In this paper, we investigate the time-dependent Ginzburg–Landau (TDGL) equations coming from the superfluid atomic Fermi gases near the Feshbach resonance from the fermion–boson model. By the method of a priori estimates, we get the existence of global attractors in the case of BCS–BEC crossover. | yue_Hant | 10,987 |
Methods for a class of discrete location problems | A generalized discrete location problem on a finite set is defined. An implicit enumeration method and two approximative ones for this problem are presented. Application to a special class of mixed 0-1 integer linear programming problems are outlined. | We present an analytical derivation of the distributed model from the experimentally well confirmed lumped approach for the description of light propagation in mode-locked fiber lasers operating in the scalar regime where the dynamics is mainly governed by the propagation of a single field component. As a limiting case of the distributed model we identify the complex cubic-quintic Ginzburg–Landau equation (CQGLE). One important result consists of deriving explicit relations between the coefficients of the distributed models to the realistic laser parameters. We numerically demonstrate that the results obtained by using the general distributed model are in very good agreement with those of the lumped model, whereas results of the CQGLE can significantly deviate for a certain range of parameters. Moreover, we demonstrate that the validity of the CQGLE approach strongly depends on the operation regime of the saturable absorber. | eng_Latn | 10,988 |
The Interior Transmission Problem: Spectral Theory | In this paper we are concerned with the interior transmission eigenvalue problem connected with a degenerate boundary problem with limited smoothness assumptions concerning its coefficients and boundary. If $\mathcal{A}_2$ denotes the Hilbert space operator induced by this boundary problem, then in order to derive information concerning the spectral properties of $\mathcal{A}_2$, we are led to consider an auxiliary boundary problem involving powers of the spectral parameter $\lambda$ up to the second order. Under our assumptions we show that the auxiliary boundary problem is parameter-elliptic, and hence we can now appeal to the theory concerning such problems to derive information pertaining to the spectral properties of the quadratic operator pencil $V_2(\lambda)$ induced by the auxiliary boundary problem. Since $\mathcal{A}_2$ is just a linearization of $V_2(\lambda)$, we thus arrive at the spectral properties of $\mathcal{A}_2$. Finally, by appealing to some known results pertaining to the uniqueness ... | AbstractWe first derive the state vector of a cascade three level atom interacting with pair coherent states in a kerr medium.It is shown by numerical calculations that the Kerr effect results in the adiabatic transition transfer phenomenon of electrons,and the superstructures in the long time behavior of the quantum statistical properties of light field appear. | eng_Latn | 10,989 |
Four-wave sum mixing in beryllium around hydrogen Lyman-α | Radiation was generated between 1210 and 1230 A by four-wave sum mixing in beryllium vapor where the 2s2 1S–2s3d1D transition was two-photon resonant. Results indicate that beryllium will be an efficient nonlinear medium in this spectral region with improvements to the stability of the furnace to allow phase matching and operation at higher pressures. | The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$. | eng_Latn | 10,990 |
Turbulent compressible convection in a deep atmosphere. I - Preliminary two-dimensional results | Two-dimensional numerical computations are used to simulate turbulent convection of a compressible fluid in a deep atmosphere. We find that ''cells'' with sizes ranging from the total depth of the convection zone to the smallest scale height at the top coexist. While the biggest cells traverse the whole zone, the smaller cells cluster toward the top. Our results also indicate that the vertical correlation length of the vertical velocity, similar to the concept fo mixing length, is proportional to the local pressure (or density) scale height. | Abstract In this paper, we investigate the time-dependent Ginzburg–Landau (TDGL) equations coming from the superfluid atomic Fermi gases near the Feshbach resonance from the fermion–boson model. By the method of a priori estimates, we get the existence of global attractors in the case of BCS–BEC crossover. | eng_Latn | 10,991 |
Dynamic of the Gaussian quantum discord and effect of non-Markovian degree | We study the dynamic of the Gaussian quantum discord in a continuous-variable system subject to a common non-Markovian environment with zero-temperature. By considering an initial two-mode Gaussian symmetric squeezed thermal state, we show that Gaussian discord has a very different dynamic characteristic in a non-Markovian evolution versus a Markov process, and can be created by the memory effect, which features non-Markovianity. We also study the relationship between Gaussian discord and the non-Markovian degree of the environment. The results may offer us an effective experimental method to get more quantum correlations. | Abstract The aim of the present paper is to give the main characteristics of the finite-source G / M /r queue in equilibrium. Here unit i stays in the source for a random time having general distribution function F i ( x ) with density f i ( x ). The service times of all units are assumed to be identically and exponentially distributed random variables with means 1/μ. It is shown that the solution to this G / M /r model is similar in most important respects to that for the M/M/ r model. | eng_Latn | 10,992 |
Improved Filon-Type Asymptotic Methods for Highly Oscillatory Differential Equations | This chapter presents an effective improvement on the existing Filon-type asymptotic methods, so that the improved methods can numerically solve a class of multi-frequency highly oscillatory second-order differential equations with a positive semi-definite singular matrix which implicitly contains and preserves the oscillatory frequencies of the underlying problem. | We study non-equilibrium velocity fluctuations in a model for the sedimentation of non-Brownian particles experiencing long-range hydrodynamic interactions. The complex behavior of these fluctuations, the outcome of the collective dynamics of the particles, exhibits many of the features observed in sedimentation experiments. In addition, our model predicts a final relaxation to an anisotropic (hydrodynamic) diffusive state that could be observed in experiments performed over longer time ranges. | eng_Latn | 10,993 |
Concentration fluctuations and the heat capacity of overcooled melts in the Fe-B system | Concentration fluctuations, excess configurational entropies, and excess configurational heat capacities of melts in the Fe-B system are calculated at different temperatures. It is shown that concentration fluctuations play an important role in the amorphization of melts and should be considered in an analysis of the propensity of melts for amorphization. | In this paper we study a degenerate evolution system ::: $\mathbf H_t +\nabla \times [|\nabla \times \mathbf H|^{p-2}\nabla \times \mathbf H]=\mathbf F$ in a bounded domain as well as its limit as $p\to \infty$ subject ::: to appropriate initial and boundary conditions. This system governs the evolution ::: of the magnetic field $\mathbf H$ in a conductive medium under the influence of a system ::: force $\mathbf F$. The system is an approximation of Bean's critical-state model for type-II superconductors. The existence, uniqueness and regularity of solutions to the ::: system are established. Moreover, it is shown that the limit of $\mathbf H(x, t)$ as $p\to \infty$ ::: is a solution to the Bean model. | eng_Latn | 10,994 |
Probing the Quantum Analog of Chaos with Atoms in External Fields | For a few years, considerable interest arises in the problem of the quantum analog of classical chaos for hamiltonian system. Among several other simple atomic physics systems, the atom in a magnetic field turns out to be the most promising prototype for tackling such questions. The classical and quantum motions are now well understood. The experimental study is possible in high Rydberg states of atoms. Throughout the study of some aspects of this problem, we demonstrate that the quantum analog of chaos presents a two-fold aspect. While the spectral properties at short range are conveniently described by Random matrix theories, a long-range order still exist in the quantum dynamics which indicates the existence of scars of symmetries. This in turn is quite clearly exhibited in the experimental data on Rydberg atoms. We finally indicate how to generalize the notions to any situation involving the Coulomb field and perturbing potentials. | The LHC experiments ATLAS and CMS have measured V+jets and ttbar+jets final states over a large energy range in data collected between 2010 and 2012 at sqrt(s) = 7 TeV and sqrt(s) = 8 TeV. The results have been compared to pQCD calculations at NLO and have been used to validate novel Monte Carlo techniques. | eng_Latn | 10,995 |
Improved loop expansion for the effective potential of coupled boson-fermion systems at finite temperature and density | The effective potential V(phi) of a scalar field theory coupled to fermions is undefined near phi = 0 if the scalar field has a spontaneously broken symmetry. This shows up in a loop expansion as an imaginary part in V(phi) which persists to all temperatures and densities, even when the symmetry is restored. This paper presents a modification of the loop expansion which yields a real V(phi) whenever the one-loop fermion corrections restore the symmetry. | In this paper, we consider the second order wave equation discretized in space by summation-by-parts-simultaneous approximation term (SBP-SAT) technique. Special emphasis is placed on the accuracy analysis of the treatment of the Dirichlet boundary condition and of the grid interface condition. The result shows that a boundary or grid interface closure with truncation error $\mathcal{O}(h^p)$ converges of order $p + 2$ if the penalty parameters are chosen carefully. We show that stability does not automatically yield a gain of two orders in convergence rate. The accuracy analysis is verified by numerical experiments. | eng_Latn | 10,996 |
Quantum Hall effect on the Lobachevsky plane | The Hall conductivity of an electron gas on the surface of constant negative curvature (the Lobachevsky plane) in the presence of an orthogonal magnetic field is investigated. It is shown that the surface curvature decreases the quantum Hall plateau widths and shifts the steps in the Hall conductivity to higher magnetic fields (or to lower values of the chemical potential). An increase of temperature results in smearing of the steps. | The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$. | eng_Latn | 10,997 |
On a class of nonlinear Schr6dinger equations | This paper concerns the existence of standing wave solutions of nonlinear Schr6dinger equations. Making a standing wave ansatz reduces the problem to that of studying the semiIinear elliptic equation: • u + b(x)u = f ( x , u), x e •". (*) The function f is assumed to be "superlinear". A special case is the power nonlinearity f ( x , z) = Izl s !z where 1 sufficient conditions for the existence of nontrivial solutions u e W m ( ~ n) are established. (Received: June 18, 1991) | We study non-equilibrium velocity fluctuations in a model for the sedimentation of non-Brownian particles experiencing long-range hydrodynamic interactions. The complex behavior of these fluctuations, the outcome of the collective dynamics of the particles, exhibits many of the features observed in sedimentation experiments. In addition, our model predicts a final relaxation to an anisotropic (hydrodynamic) diffusive state that could be observed in experiments performed over longer time ranges. | eng_Latn | 10,998 |
Equations of Langmuir turbulence and nonlinear Schrödinger equation: Smoothness and approximation | We consider the following family of systems parametrized by e > 0, which describe Langmuir's turbulence. In the case where initial data are sufficiently small, we study the asymptotic behaviour of the solutions (Ee, ne) when e goes to zero, for d = 1, 2, 3. Namely, we state convergence results of (Ee, ne) to the couple (E, − ¦E¦2) where E is the solution of the nonlinear Schrodinger equation: Moreover, in three dimensions we show that the smooth solution (Ee, ne) is defined on [0, Tmax(e)[with Tmax(e) going to infinity as e goes to 0. | We apply the $\delta$-expansion perturbation scheme to the $\lambda \phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\delta$-expansion the interaction term is written as $\lambda (\phi^{2})^{ 1 + \delta}$ and $\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\delta$. The results are compared with the usual loop-expansion at finite temperature. | eng_Latn | 10,999 |
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