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suppose that $ \ { a _ j \ } \ in \ ell ^ 1 $, and suppose that for any sequence $ ( t _ n ) $ of integers there exits a constant $ c _ 1 > 0 $ such that $ $ \ sharp \ left \ { k \ in \ mathbb { z } : \ sup _ { n \ geq 1 } \ left | \ sum _ { i \ in \ mathcal { b } _ n - t _ n } \! \! \! \ raise { 1. 9ex } \ hbox { $ \ scriptsize \ prime $ } \ ; \ frac { a _ { k + i } } { i } \ right | > \ lambda \ right \ } \ \ \ leq c _ 1 \ sharp \ left \ { k \ in \ mathbb { z } : \ sup _ { n \ geq 1 } \ left | \ sum _ { i \ in \ mathcal { b } _ n } \! \! \ raise { 1. 9ex } \ hbox { $ \ scriptsize \ prime $ } \ ; \ frac { a _ { k + i } } { i } \ right | > \ lambda \ right \ }, $ $ for all $ \ lambda > 0 $, where $ \ mathcal { b } _ n = \ { - n, - ( n - 1 ), - ( n - 2 ), \ dots, n - 2, n - 1, n \ } $. then there is a constant $ c _ 2 > 0 $ which does not depend on the sequence $ \ { a _ j \ } $ such that $ $ \ sum _ { n = 1 } ^ \ infty \ sharp \ left \ { k \ in \ mathbb { z } : \ left | \ sum _ { i = - n } ^ { n } \! \! \ raise { 1. 9ex } \ hbox { $ \ scriptsize \ prime $ } \ ; \ frac { a _ { k + i } } { i } \ right | > \ lambda \ right \ } \ leq \ frac { c _ 2 } { \ lambda } \ sum _ { i = - \ infty } ^ { \ infty } | a _ i | $ $ for all $ \ lambda > 0 $. let $ ( x, \ mathscr { b }, \ mu ) $ be a
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arxiv:2009.05822
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it is shown that the higher order supersymmetric partners of the harmonic oscillator hamiltonian provide the simplest non - trivial realizations of the polynomial heisenberg algebras. a linearized version of the corresponding annihilation and creation operator leads to a fock representation which is the same as for the harmonic oscillator hamiltonian
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arxiv:quant-ph/0011004
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in this paper, i consider a simple heterogeneous agents model of a production economy with uncertain climate change and examine constrained efficient carbon taxation. if there are frictionless, complete financial markets, the simple model predicts a unique pareto - optimal level of carbon taxes and abatement. in the presence of financial frictions, however, the optimal level of abatement cannot be defined without taking a stand on how abatement costs are distributed among individuals. i propose a simple linear cost - sharing scheme that has several desirable normative properties. i use calibrated examples of economies with incomplete financial markets and / or limited market participation to demonstrate that different schemes to share abatement costs can have large effects on optimal abatement levels and that the presence of financial frictions can increase optimal abatement by a factor of three relative to the case of frictionless financial market.
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arxiv:2210.09066
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the interplay between humans and generative ai ( gen ai ) draws an insightful parallel with the dynamic relationship between giraffes and acacias on the african savannah. just as giraffes navigate the acacia ' s thorny defenses to gain nourishment, humans engage with gen ai, maneuvering through ethical and operational challenges to harness its benefits. this paper explores how, like young giraffes that are still mastering their environment, humans are in the early stages of adapting to and shaping gen ai. it delves into the strategies humans are developing and refining to help mitigate risks such as bias, misinformation, and privacy breaches, that influence and shape gen ai ' s evolution. while the giraffe - acacia analogy aptly frames human - ai relations, it contrasts nature ' s evolutionary perfection with the inherent flaws of human - made technology and the tendency of humans to misuse it, giving rise to many ethical dilemmas. through the hhh framework we identify pathways to embed values of helpfulness, honesty, and harmlessness in ai development, fostering safety - aligned agents that resonate with human values. this narrative presents a cautiously optimistic view of human resilience and adaptability, illustrating our capacity to harness technologies and implement safeguards effectively, without succumbing to their perils. it emphasises a symbiotic relationship where humans and ai continually shape each other for mutual benefit.
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arxiv:2407.11360
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bidirected graphs ( earlier studied by edmonds, johnson and, in equivalent terms of skew - symmetric graphs, by tutte, goldberg, karzanov, and others ) proved to be a useful unifying language for describing both flow and matching problems. in this paper we extend the notion of ear decomposition to the class of strongly connected bidirected graphs. in particular, our results imply two ear theorem on matching covered graphs of lov \ ' asz and plummer. the proofs given here are self - contained except for standard barrier theorem on skew - symmetric graphs.
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arxiv:math/0609221
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we show that the majorana fermion zero modes in the cores of odd winding number vortices of a 2d $ p _ x + ip _ y $ - paired superconductor is due to an index theorem. this theorem is analogous to that proven by jackiw and rebbi for the existence of localized dirac fermion zero modes on the mass domain walls of a 1d dirac theory. the important difference is that, in our case, the theorem is proven for a two component fermion theory where the first and second components are related by parity reversal and hermitian conjugation.
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arxiv:cond-mat/0609556
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runtime verification ( rv ) has the potential to enable the safe operation of safety - critical systems that are too complex to formally verify, such as robot operating system 2 ( ros2 ) applications. writing correct monitors can itself be complex, and errors in the monitoring subsystem threaten the mission as a whole. this paper provides an overview of a formal approach to generating runtime monitors for autonomous robots from requirements written in a structured natural language. our approach integrates the formal requirement elicitation tool ( fret ) with copilot, a runtime verification framework, through the ogma integration tool. fret is used to specify requirements with unambiguous semantics, which are then automatically translated into temporal logic formulae. ogma generates monitor specifications from the fret output, which are compiled into hard - real time c99. to facilitate integration of the monitors in ros2, we have extended ogma to generate ros2 packages defining monitoring nodes, which run the monitors when new data becomes available, and publish the results of any violations. the goal of our approach is to treat the generated ros2 packages as black boxes and integrate them into larger ros2 systems with minimal effort.
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arxiv:2209.14030
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relations between the string topology of chas and sullivan and the homotopy skein modules of hoste and przytycki are studied. this provides new insight into the structure of homotopy skein modules and their meaning in the framework of quantum topology. our results can be considered as weak extensions to all orientable 3 - manifolds of classical results by turaev and goldman concerning intersection and skein theory on oriented surfaces.
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arxiv:math/0211392
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it has been argued that if multiple spin wave modes are competing for the same centrally located energy source, as in a nanocontact spin torque oscillator, that only one mode should survive in the steady state. here, the experimental conditions necessary for mode coexistence are explored. mode coexistence is facilitated by the local field asymmetries induced by the spatially inhomogeneous oersted field, which leads to a physical separation of the modes, and is further promoted by spin wave localization at reduced applied field angles. finally, both simulation and experiment reveal a low frequency signal consistent with the intermodulation of two coexistent modes.
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arxiv:1303.7148
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we present h band ( 1. 53 - 1. 69 micron ) spectra of 57 isolated be stars of spectral types o9 - b9 and luminosity classes iii, iv & v. the hi brackett ( n - 4 ) series is seen in emission from br 11 - 18, and feii emission is also apparent for a subset of those stars with hi emission. no emission from species with a higher excitation temperature, such as he ii or ciii is seen, and no forbidden line emission is present. a subset of 12 stars show no evidence for emission from any species ; these stars appear indistinguishable from normal b stars of a comparable spectral type. in general the line ratios constructed from the transitions in the range br 11 - 18 do not fit case b recombination theory particularly well. strong correlations between the line ratios with br - gamma and spectral type are found. these results most likely represent systematic variations in the temperature and ionization of the circumstellar disc with spectral type. weak correlations between the line widths and projected rotational velocity of the stars are observed ; however no systematic trend for increasing line width through the brackett series is observed.
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arxiv:astro-ph/0103259
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correlations of two charged identical kaons ( $ { \ rm k } ^ { \ rm ch } { \ rm k } ^ { \ rm ch } $ ) are measured in pp collisions at $ \ sqrt { s } = 7 $ ~ tev by the alice experiment at the large hadron collider ( lhc ). one - dimensional $ { \ rm k } ^ { \ rm ch } { \ rm k } ^ { \ rm ch } $ correlation functions are constructed in three multiplicity and four transverse momentum ranges. the $ { \ rm k } ^ { \ rm ch } { \ rm k } ^ { \ rm ch } $ femtoscopic source parameters $ r $ and $ \ lambda $ are extracted. the $ { \ rm k } ^ { \ rm ch } { \ rm k } ^ { \ rm ch } $ correlations show a slight increase of femtoscopic radii with increasing multiplicity and a slight decrease of radii with increasing transverse momentum. these trends are similar to the ones observed for $ \ pi \ pi $ and $ { \ rm k } ^ 0 _ { \ rm s } { \ rm k } ^ 0 _ { \ rm s } $ correlations in pp and heavy - ion collisions. however at high multiplicities, there is an indication that the one - dimensional correlation radii for charged kaons are larger than those for pions in contrast to what was observed in heavy - ion collisions at rhic.
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arxiv:1212.5958
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prelithiation as a facile and effective method to compensate the lithium inventory loss in the initial cycle has progressed considerably both on anode and cathode sides. however, much less research has been devoted to the prelithiation effect on the interface stabilization for long - term cycling of si - based anodes. an in - depth quantitative analysis of the interface that form during the prelithiation of sio $ _ x $ is presented here and the results are compared with prelithiaton of si anodes. local structure probe combined with detailed electrochemical analysis reveals that a characteristic mosaic interface is formed on both prelithiated sio $ _ x $ and si anodes. this mosaic interface containing multiple lithium silicates phases, is fundamentally different from the solid electrolyte interface ( sei ) formed without prelithiation. the ideal conductivity and mechanical properties of lithium silicates enable improved cycling stability of both prelithiated anodes. with a higher ratio of lithium silicates due to the oxygen participation, prelithiated sio $ _ { 1. 3 } $ anode improves the initial coulombic efficiency to 94 % in full cell and delivers good cycling retention after hundreds cycles under lean electrolyte conditions. the insights provided in this work could be used to further optimize high si loading based anode in future high energy density batteries.
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arxiv:2304.06817
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a general method to find an effective potential of interaction between far separated 2d and 3d solitons is elaborated, including the case of 2d vortex solitons. the method is based on explicit calculation of the overlapping term in the full hamiltonian of the system ( _ without _ assuming that the ` ` tail ' ' of each soliton is not affected by its interaction with the other soliton, and, in fact, _ without _ knowing the exact form of the solution for an isolated soliton - the latter problem is circumvented by reducing a bulk integral to a surface one ). the result is obtained in an explicit form that does not contain an artificially introduced radius of the overlapping region. the potential applies to spatial and spatiotemporal solitons in nonlinear optics, where it may help to solve various dynamical problems : collisions, formation of bound states ( bs ' s ), etc. in particular, an orbiting bs of two solitons is always unstable. in the presence of weak dissipation and gain, the effective potential can also be derived, giving rise to bound states similar to those recently studied in 1d models.
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arxiv:patt-sol/9809009
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we introduce a class of perverse sheaves on a partial flag manifold of a connected reductive group g defined over a finite field which are equivariant under the action of the group of rational points of g. the definition of this class is similar to the definition of parabolic character sheaves.
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arxiv:math/0610406
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we propose an extension to multivariate time series of the phase - randomized fourier - transform algorithm for generating surrogate data. such surrogate data sets must mimic not only the autocorrelations of each of the variables in the original data set, they must mimic the cross - correlations { \ em between } all the variables as well. the method is applied both to a simulated example ( the three components of the lorenz equations ) and to data from a multichannel electroencephalogram.
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arxiv:comp-gas/9405002
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plank ' s constant is a fundamental constant in physical sciences and millikan received noble prize for obtaining it experimentally in 1923. as the technology of solid state electronic devices developed, an experiment was designed and adapted to determine the plank ' s constant using led. herrmann and sch \ " atzle questioned the validity of this experiment on the basis of the diode equation and their approach was further discussed by morehouse. in this article, the validity of this experiment is revisited.
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arxiv:1811.05799
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the role of cr incorporation into the zno were probed through investigations into the structural, optical and magnetic properties. zn1 - xcrxo with x = 0, 0. 01, 0. 03 and 0. 05, nanoparticles were prepared by solution combustion method. powder x - ray diffraction ( xrd ) results reveal, all the synthesized samples are in single hexagonal wurtzite crystal structures, indicating that cr3 + ions substitute the zn2 + ions without altering the structure. the crystallite size and microstrain were calculated using the willamson - hall method and found to be 36 + - 2 nm for zno and it reduced with the increase of cr dopant concentration to 20 + - 2 nm for zn0. 95cr0. 05o. transmission electron microscopy ( tem ) revealed that the particle size were 48 + - 2 nm, 29 + - 2 nm and 25 + - 2 nm for the zn1 - xcrxo with x = 0, 0. 03 and 0. 05, respectively. tem morphology indicated particles are agglomerated in the doped samples. the band - gap decreases slightly from 3. 305 + - 0. 003 ev to 3. 292 + - 0. 003 ev with increase of cr content from x = 0 to 0. 05, respectively. photoluminescence measurements revealed the presence of defects in the samples, associated with zinc vacancies and singly ionized oxygen vacancy. the field - dependent magnetization measurements of zno and cr - doped zno were carried out using a vibrating sample magnetometer ( vsm ) at 300 k. all the samples exhibits ferromagnetic behavior. this long - range ferromagnetism ordering observed in zno is explained based on bound magnetic polaron ( bmp ) mechanism. the singly ionized oxygen vacancies playing a crucial role in observed room temperature ferromagnetism ( rtfm ) in zno. there is a sufficient amount of bmps formed in cr doped zno because of the defects present in these samples. therefore, the overlapping of bmps results in the rtfm. however, the antiferromagnetic coupling at a higher doping concentration of cr, weakens the observed rtfm.
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arxiv:2111.07264
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it is of significance for an agent to learn a widely applicable and general - purpose policy that can achieve diverse goals including images and text descriptions. considering such perceptually - specific goals, the frontier of deep reinforcement learning research is to learn a goal - conditioned policy without hand - crafted rewards. to learn this kind of policy, recent works usually take as the reward the non - parametric distance to a given goal in an explicit embedding space. from a different viewpoint, we propose a novel unsupervised learning approach named goal - conditioned policy with intrinsic motivation ( gpim ), which jointly learns both an abstract - level policy and a goal - conditioned policy. the abstract - level policy is conditioned on a latent variable to optimize a discriminator and discovers diverse states that are further rendered into perceptually - specific goals for the goal - conditioned policy. the learned discriminator serves as an intrinsic reward function for the goal - conditioned policy to imitate the trajectory induced by the abstract - level policy. experiments on various robotic tasks demonstrate the effectiveness and efficiency of our proposed gpim method which substantially outperforms prior techniques.
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arxiv:2104.05043
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we study the modified reissner nordstrom metric in the unimodular gravity. so far the spherical symmetric einstein field equation in unimodular gravity has been studied in the absence of any source. we consider static electric and magnetic charge as source. we solve for maxwell equations in unimodular gravitational background. we show that in unimodular gravity the electromagnetic field strength tensor is modified. we also show that the solution in unimodular gravity differs from the usual r - n metric in einstein gravity with some corrections. we further study the thermodynamical properties of the r - n black - hole solution in this theory.
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arxiv:1610.07661
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electric fields are central to the operation of optoelectronic devices based on conjugated polymers since they drive the recombination of electrons and holes to excitons in organic light - emitting diodes but are also responsible for the dissociation of excitons in solar cells. one way to track the microscopic effect of electric fields on charge carriers formed under illumination of a polymer film is to exploit the fluorescence arising from delayed recombination of carrier pairs, a process which is fundamentally spin dependent. such spin - dependent recombination can be probed directly in fluorescence, by optically detected magnetic resonance ( odmr ). depending on the relative orientation, an electric field may either dissociate or stabilize an electron - hole carrier pair. we find that the odmr signal in a polymer film is quenched in an electric field, but that, at fields exceeding 1 mv / cm, this quenching saturates. this finding contrasts the complete odmr suppression that was previously observed in polymeric photodiodes, indicating that exciton - charge interactions - - - analogous to auger recombination in crystalline semiconductors - - - may constitute the dominant carrier - pair dissociation process in organic electronics.
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arxiv:1806.03805
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recent observations of h2 and h3 + in diffuse interstellar sightlines revealed a difference in the nuclear spin excitation temperatures of the two species. this discrepancy comes as a surprise, as h3 + and h2 should undergo frequent thermalizing collisions in molecular clouds. non - thermal behavior of the fundamental h3 + / h2 collision system at low temperatures was considered as a possible cause for the observed irregular populations. here, we present measurements of the steady - state ortho / para ratio of h3 + in collisions with h2 molecules in a temperature - variable radiofrequency ion trap between 45 - 100 k. the experimental results are close to the expected thermal outcome and they agree very well with a previous micro - canonical model. we briefly discuss the implications of the experimental results for the chemistry of the diffuse interstellar medium.
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arxiv:1209.3041
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consider a principal who wants to search through a space of stochastic solutions for one maximizing their utility. if the principal cannot conduct this search on their own, they may instead delegate this problem to an agent with distinct and potentially misaligned utilities. this is called delegated search, and the principal in such problems faces a mechanism design problem in which they must incentivize the agent to find and propose a solution maximizing the principal ' s expected utility. following prior work in this area, we consider mechanisms without payments and aim to achieve a multiplicative approximation of the principal ' s utility when they solve the problem without delegation. in this work, we investigate a natural and recently studied generalization of this model to multiple agents and find nearly tight bounds on the principal ' s approximation as the number of agents increases. as one might expect, this approximation approaches 1 with increasing numbers of agents, but, somewhat surprisingly, we show that this is largely not due to direct competition among agents.
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arxiv:2411.00181
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we present a new method to account for coherence length effects in a semi - classical transport model. this allows us to describe photo - and electroproduction at large nuclei ( a > 12 ) and high energies using a realistic coupled channel description of the final state interactions that goes beyond simple glauber theory. we show that the purely absorptive treatment of the final state interactions can lead to wrong estimates of color transparency and formation time effects in particle production. as an example, we discuss exclusive rho ^ 0 photoproduction on pb at a photon energy of 7 gev as well as k ^ + production in the photon energy range 1 - 7 gev.
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arxiv:nucl-th/0203052
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in this paper, regularized lightweight deep convolutional neural network models, capable of effectively operating in real - time on devices with restricted computational power for high - resolution video input are proposed. furthermore, a novel regularization method motivated by the quadratic mutual information, in order to improve the generalization ability of the utilized models is proposed. extensive experiments on various binary classification problems involved in autonomous systems are performed, indicating the effectiveness of the proposed models as well as of the proposed regularizer.
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arxiv:2108.11774
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it seems that the wealth of information revealed by the multi - messenger observations of the binary neutron star ( ns ) merger event, gw170817 / grb 170817a / kilonova at2017gfo, places irreconcilable constraints to models of the prompt emission of this gamma - ray burst ( grb ). the observed time delay between the merger of the two nss and the trigger of the grb and the thermal tail of the prompt emission can hardly be reproduced by these models simultaneously. we argue that the merger remnant should be an ns ( last for, at least, a large fraction of 1s ), and that the difficulty can be alleviated by the delayed formation of the accretion disk due to the absorption of high - energy neutrinos emitted by the ns and the delayed emergence of an effective viscous in the disk. further, we extend the consideration of the effect of the energy deposition of neutrinos emitted from the ns. if the ns is the central object of a grb with a distance and duration similar to that of grb 170817a, thermal emission of the thermal bubble inflated by the ns after the termination of accretion may be detectable. if our scenario is verified, it would be of interest to investigate the cooling of nascent nss.
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arxiv:2307.11098
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using the high temperature approximation we study, within the linear response theory, the wake in the quark - gluon plasma by a fast parton owing to dynamical screening in the space like region. when the parton moves with a speed less than the average speed of the plasmon, we find that the wake structure corresponds to a screening charge cloud traveling with the parton with one sign flip in the induced charge density resulting in a lennard - jones type potential in the outward flow with a short range repulsive and a long range attractive part. on the other hand if the parton moves with a speed higher than that of plasmon, the wake structure in the induced charge density is found to have alternate sign flips and the wake potential in the outward flow oscillates analogous to cerenkov like wave generation with a mach cone structure trailing the moving parton. the potential normal to the motion of the parton indicates a transverse flow in the system. we also calculate the potential due to a color dipole and discuss consequences of possible new bound states and $ j / \ psi $ suppression in the quark - gluon plasma.
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arxiv:hep-ph/0606316
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the coordinate transformation technique is applied to the design of perfect lenses and superlenses. in particular, anisotropic metamaterials that magnify two - dimensional planar images beyond the diffraction limit are designed by the use of oblate spheroidal coordinates. the oblate spheroidal perfect lens or superlens can naturally be used in reverse for lithography of planar subwavelength patterns.
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arxiv:0708.0262
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in this paper, we study a bayesian tensor train ( tt ) decomposition method to recover streaming data by approximating the latent structure in high - order streaming data. drawing on the streaming variational bayes method, we introduce the tt format into bayesian tensor decomposition methods for streaming data, and formulate posteriors of tt cores. thanks to the bayesian framework of the tt format, the proposed algorithm ( sptt ) excels in recovering streaming data with high - order, incomplete, and noisy properties. the experiments in synthetic and real - world datasets show the accuracy of our method compared to state - of - the - art bayesian tensor decomposition methods for streaming data.
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arxiv:2302.12148
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this paper is concerned with the derivation of a two - component system modelling shallow - water waves with constant vorticity under the camassa - holm scaling from our newly established green - naghdi equations with a linear shear. it is worth pointing out that the $ \ rho $ component in this new system is quite different from the previous two - component system due to the effects of both vorticity and larger amplitude. we then establish the local well - posedness of this new system in besov spaces, and present a blow - up criterion. we finally give a sufficient condition for global strong solutions to the system in some special case.
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arxiv:2406.08874
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an issue which has attracted increasing attention in contemporary researches are kirkwood - - dirac quasiprobabilities. list of their use includes many questions of quantum physics. applications of complex tight frames in quantum information science were recently demonstrated. it is shown in this paper that quasiprobabilities naturally appear in the context of unravelings of a quantum channel. using vectors of the given tight frame to build principal kraus operators generates quasiprobabilities with interesting properties. for an equiangular tight frame, we characterize the hilbert - - schmidt and spectral norms of the matrix consisted of quasiprobabilities. hence, novel uncertainty relations in terms of r \ ' { e } nyi and tsallis entropies are obtained. new inequalities for characterizing the location of eigenvalues are derived. they give an alternative to estimating on the base of ger \ v { s } gorin ' s theorem. a utility of the presented inequalities is exemplified with symmetric informationally complete measurement in dimension two.
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arxiv:2304.14038
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two main uses : offer internet access to populations in isolated villages, and to provide healthcare to isolated communities. in the case of the latter example, it connects the central hospital in iquitos to 15 medical outposts which are intended for remote diagnosis. = = = work habits = = = access to wi - fi in public spaces such as cafes or parks allows people, in particular freelancers, to work remotely. while the accessibility of wi - fi is the strongest factor when choosing a place to work ( 75 % of people would choose a place that provides wi - fi over one that does not ), other factors influence the choice of specific hotspots. these vary from the accessibility of other resources, like books, the location of the workplace, and the social aspect of meeting other people in the same place. moreover, the increase of people working from public places results in more customers for local businesses thus providing an economic stimulus to the area. additionally, in the same study it has been noted that wireless connection provides more freedom of movement while working. both when working at home or from the office it allows the displacement between different rooms or areas. in some offices ( notably cisco offices in new york ) the employees do not have assigned desks but can work from any office connecting their laptop to wi - fi hotspot. = = = housing = = = the internet has become an integral part of living. as of 2016, 81. 9 % of american households have internet access. additionally, 89 % of american households with broadband connect via wireless technologies. 72. 9 % of american households have wi - fi. wi - fi networks have also affected how the interior of homes and hotels are arranged. for instance, architects have described that their clients no longer wanted only one room as their home office, but would like to work near the fireplace or have the possibility to work in different rooms. this contradicts architect ' s pre - existing ideas of the use of rooms that they designed. additionally, some hotels have noted that guests prefer to stay in certain rooms since they receive a stronger wi - fi signal. = = health concerns = = the world health organization ( who ) says, " no health effects are expected from exposure to rf fields from base stations and wireless networks ", but notes that they promote research into effects from other rf sources. ( a category used when " a causal association is considered credible, but when chance, bias or confounding cannot be ruled out with reasonable confidence " ), this classification was based on risks associated with wireless phone
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https://en.wikipedia.org/wiki/Wi-Fi
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we give a cohomological classification of vector bundles of rank $ 2 $ on a smooth affine threefold over an algebraically closed field having characteristic unequal to $ 2 $. as a consequence we deduce that cancellation holds for rank $ 2 $ vector bundles on such varieties. the proofs of these results involve three main ingredients. first, we give a description of the first non - stable $ { \ mathbb a } ^ 1 $ - homotopy sheaf of the symplectic group. second, these computations can be used in concert with f. morel ' s $ { \ mathbb a } ^ 1 $ - homotopy classification of vector bundles on smooth affine schemes and obstruction theoretic techniques ( stemming from a version of the postnikov tower in $ { \ mathbb a } ^ 1 $ - homotopy theory ) to reduce the classification results to cohomology vanishing statements. third, we prove the required vanishing statements.
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arxiv:1204.0770
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in this paper we elaborate on the gauge invariant frame - like lagrangian description for the wide class of the so - called infinite ( or continuous ) spin representations of poincar \ ' e group. we use our previous results on the gauge invariant formalism for the massive mixed symmetry fields corresponding to the young tableau with two rows y ( k, l ) ( y ( k + 1 / 2, l + 1 / 2 ) for the fermionic case ). we have shown that the corresponding infinite spin solutions can be constructed as a limit where k goes to infinity, while l remain to be fixed and label different representations. moreover, our gauge invariant formalism provides a natural generalization to ( anti ) de sitter spaces as well. as in the completely symmetric case considered earlier by metsaev we have found that there are no unitary solutions in de sitter space, while there exists a rather wide spectrum of anti de sitter ones. in this, the question what representations of the anti de sitter group such solutions correspond to remains to be open.
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arxiv:1711.08223
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we investigate the post - quantum security of the encrypted key exchange ( eke ) protocols based on some basic physical parameters of ion - trap quantum computer, and show that the eke protocol with a 40 - bit password will be secure against a quantum adversary with several ion - trap quantum computers. we present a password encrypted no - key protocol to resist middle - man attack, and prove that it is also with the post - quantum security. the analysis presented here is probably of general meaning for the security evaluation of various hybrid cryptosystems.
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arxiv:1305.5640
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over the past two decades, vibrational resonance has garnered significant interest and evolved into a prominent research field. classical vibrational resonance examines the response of a nonlinear system excited by two signals : a weak, slowly varying characteristic signal, and a fast - varying auxiliary signal. the characteristic signal operates on a much longer time scale than the auxiliary signal. through the cooperation of the nonlinear system and these two excitations, the faint input can be substantially amplified, showcasing the constructive role of the fast - varying signal. since its inception, vibrational resonance has been extensively studied across various disciplines, including physics, mathematics, biology, neuroscience, laser science, chemistry, and engineering. here, we delve into a detailed discussion of vibrational resonance and the most recent advances, beginning with an introduction to characteristic signals commonly used in its study. furthermore, we compile numerous nonlinear models where vibrational resonance has been observed to enhance readers ' understanding and provide a basis for comparison. subsequently, we present the metrics used to quantify vibrational resonance, as well as offer a theoretical formulation. this encompasses the method of direct separation of motions, linear and nonlinear vibrational resonance, re - scaled vibrational resonance, ultrasensitive vibrational resonance, and the role of noise in vibrational resonance. later, we showcase two practical applications of vibrational resonance : one in image processing and the other in fault diagnosis. this presentation offers a comprehensive and versatile overview of vibrational resonance, exploring various facets and highlighting promising avenues for future research in both theory and engineering applications.
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arxiv:2403.06997
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using linear perturbation theory, we investigate the torque exerted on a low - mass planet embedded in a gaseous protoplanetary disc with finite thermal diffusivity. when the planet does not release energy into the ambient disc, the main effect of thermal diffusion is the softening of the enthalpy peak near the planet, which results in the appearance of two cold and dense lobes on either side of the orbit, of size smaller than the thickness of the disc. the lobes exert torques of opposite sign on the planet, each comparable in magnitude to the one - sided lindblad torque. when the planet is offset from corotation, the lobes are asymmetric and the planet experiences a net torque, the ` cold ' thermal torque, which has a magnitude that depends on the relative value of the distance to corotation to the size of the lobes $ \ sim \ sqrt { \ chi / \ omega _ p } $, $ \ chi $ being the thermal diffusivity and $ \ omega _ p $ the orbital frequency. we believe that this effect corresponds to the phenomenon named ` cold finger ' recently reported in numerical simulations, and we argue that it constitutes the dominant mode of migration of sub - earth - mass objects. when the planet is luminous, the heat released into the ambient disc results in an additional disturbance that takes the form of hot, low - density lobes. they give a torque, named heating torque in previous work, that has an expression similar, but of opposite sign, to the cold thermal torque.
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arxiv:1708.09807
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we investigate proper scoring rules for continuous distributions on the real line. it is known that the log score is the only such rule that depends on the quoted density only through its value at the outcome that materializes. here we allow further dependence on a finite number $ m $ of derivatives of the density at the outcome, and describe a large class of such $ m $ - local proper scoring rules : these exist for all even $ m $ but no odd $ m $. we further show that for $ m \ geq2 $ all such $ m $ - local rules can be computed without knowledge of the normalizing constant of the distribution.
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arxiv:1101.5011
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hh 212 is a nearby ( 400 pc ) highly collimated protostellar jet powered by a class 0 source in orion. we have mapped the inner 80 " ( ~ 0. 16 pc ) of the jet in sio ( j = 8 - 7 ) and co ( j = 3 - 2 ) simultaneously at ~ 0. 5 resolution with the atacama millimeter / submillimeter array at unprecedented sensitivity. the jet consists of a chain of knots, bow shocks, and sinuous structures in between. as compared to that seen in our previous observations with the submillimeter array, it appears to be more continuous, especially in the northern part. some of the knots are now seen associated with small bow shocks, with their bow wings curving back to the jet axis, as seen in pulsed jet simulations. two of them are reasonably resolved, showing kinematics consistent with sideways ejection, possibly tracing the internal working surfaces formed by a temporal variation in the jet velocity. in addition, nested shells are seen in co around the jet axis connecting to the knots and bow shocks, driven by them. the proper motion of the jet is estimated to be ~ 115 + - 50 km / s, comparing to our previous observations. the jet has a small semi - periodical wiggle, with a period of ~ 93 yrs. the amplitude of the wiggle first increases with the distance from the central source and then stays roughly constant. one possible origin of the wiggle could be the kink instability in a magnetized jet.
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arxiv:1503.07362
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. = = people = = four scientific researchers at nist have been awarded nobel prizes for work in physics : william daniel phillips in 1997, eric allin cornell in 2001, john lewis hall in 2005 and david jeffrey wineland in 2012, which is the largest number for any us government laboratory. all four were recognized for their work related to laser cooling of atoms, which is directly related to the development and advancement of the atomic clock. in 2011, dan shechtman was awarded the nobel prize in chemistry for his work on quasicrystals in the metallurgy division from 1982 to 1984. in addition, john werner cahn was awarded the 2011 kyoto prize for materials science, and the national medal of science has been awarded to nist researchers cahn ( 1998 ) and wineland ( 2007 ). other notable people who have worked at nbs or nist include : = = directors = = since 1989, the director of nist has been a presidential appointee and is confirmed by the united states senate, and since that year the average tenure of nist directors has fallen from 11 years to 2 years in duration. since the 2011 reorganization of nist, the director also holds the title of under secretary of commerce for standards and technology. seventeen individuals have officially held the position ( in addition to seven acting directors who have served on a temporary basis ). = = patents = = nist holds patents on behalf of the federal government of the united states, with at least one of them being custodial to protect public domain use, such as one for a chip - scale atomic clock, developed by a nist team as part of a darpa competition. = = controversy regarding nist standard sp 800 - 90 = = in september 2013, both the guardian and the new york times reported that nist allowed the national security agency ( nsa ) to insert a cryptographically secure pseudorandom number generator called dual ec drbg into nist standard sp 800 - 90 that had a kleptographic backdoor that the nsa can use to covertly predict the future outputs of this pseudorandom number generator thereby allowing the surreptitious decryption of data. both papers report that the nsa worked covertly to get its own version of sp 800 - 90 approved for worldwide use in 2006. the whistle - blowing document states that " eventually, nsa became the sole editor ". the reports confirm suspicions and technical grounds publicly raised by cryptographers in 2007 that the ec - drbg could contain a kleptographic back
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https://en.wikipedia.org/wiki/National_Institute_of_Standards_and_Technology
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we provide a new estimate of the long - distance component to the radiative transition $ b \ to \ rho \ gamma $. our mechanism involves the soft - scattering of on - shell hadronic products of nonleptonic $ b $ decay, as in the chain $ b \ to \ rho \ rho \ to \ rho \ gamma $. we employ a phenomenological fit to scattering data to estimate the effect. the specific intermediate states considered here modify the $ b \ to \ rho \ gamma $ decay rate at roughly the $ 5 \ to 8 % $ level, although the underlying effect has the potential to be larger. contrary to other mechanisms of long distance physics which have been discussed in the literature, this yields a non - negligible modification of the $ b ^ 0 \ to \ rho ^ 0 \ gamma $ channel and hence will provide an uncertainty in the extraction of $ v _ { td } $. this mechanism also affects the isospin relation between the rates for $ b ^ - \ to \ rho ^ - \ gamma $ and $ b ^ 0 \ to \ rho ^ 0 \ gamma $ and may generate cp asymmetries at experimentally observable levels.
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arxiv:hep-ph/9609530
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a single neuron is known to generate almost identical spike trains when the same fluctuating input is repeatedly applied. here, we study the reliability of spike firing in a pulse - coupled network of oscillator neurons receiving fluctuating inputs. we can study the precise responses of the network as synchronization between uncoupled copies of the network by a common noisy input. to study the noise - induced synchronization between networks, we derive a self - consistent equation for the distribution of spike - time differences between the networks. solving this equation, we elucidate how the spike precision changes as a function of the coupling strength.
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arxiv:0906.3940
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##eq x : x \ in s \ }, } is a principal ultrafilter on x { \ displaystyle x }. moreover, every principal ultrafilter on x { \ displaystyle x } is necessarily of this form. the ultrafilter lemma implies that non - principal ultrafilters exist on every infinite set ( these are called free ultrafilters ). every net valued in a singleton subset x { \ displaystyle x } of is an ultranet in x. { \ displaystyle x. } the bell number integer sequence counts the number of partitions of a set ( oeis : a000110 ), if singletons are excluded then the numbers are smaller ( oeis : a000296 ). = = in category theory = = structures built on singletons often serve as terminal objects or zero objects of various categories : the statement above shows that the singleton sets are precisely the terminal objects in the category set of sets. no other sets are terminal. any singleton admits a unique topological space structure ( both subsets are open ). these singleton topological spaces are terminal objects in the category of topological spaces and continuous functions. no other spaces are terminal in that category. any singleton admits a unique group structure ( the unique element serving as identity element ). these singleton groups are zero objects in the category of groups and group homomorphisms. no other groups are terminal in that category. = = definition by indicator functions = = let s be a class defined by an indicator function b : x → { 0, 1 }. { \ displaystyle b : x \ to \ { 0, 1 \ }. } then s is called a singleton if and only if there is some y ∈ x { \ displaystyle y \ in x } such that for all x ∈ x, { \ displaystyle x \ in x, } b ( x ) = ( x = y ). { \ displaystyle b ( x ) = ( x = y ). } = = definition in principia mathematica = = the following definition was introduced in principia mathematica by whitehead and russell ι { \ displaystyle \ iota } ‘ x = y ^ ( y = x ) { \ displaystyle x = { \ hat { y } } ( y = x ) } df. the symbol ι { \ displaystyle \ iota } ‘ x { \ displaystyle x } denotes the singleton { x } { \ displaystyle \ { x \ } } and y
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https://en.wikipedia.org/wiki/Singleton_(mathematics)
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we calculate for la2cuo4 the phonon - induced redistribution of the electronic charge density in the insulating, the underdoped pseudogap and the more conventional metallic state as obtained for optimal and overdoping, respectively. the investigation is performed for the anomalous high - frequency - oxygen - bond stretching modes ( obsm ) which experimentally are known to display a strong softening of the frequencies upon doping in the cuprates. this most likely generic anomalous behaviour of the obsm has been shown to be due to a strong nonlocal electron - phonon interaction ( epi ) mediated by charge fluctuations on the ions. the modeling of the competing electronic states of the cuprates is achieved in terms of consecutive orbital selective incompressibility - compressibility transitions for the charge response. we demonstrate that the softening of the obsm in these states is due to nonlocally induced dynamic charge inhomogenities in form of charge stripes along the cuo bonds with different orbital character. thus, a multi - orbital approach is essential for the cuo plane. the dynamic charge inhomogeneities may in turn be considered as precursors of static charge stripe order as recently observed in la $ _ { 2 - x } $ ba $ _ { x } $ cuo $ _ { 4 } $ in a broad range of doping around x = 1 / 8. the latter may trigger a reconstruction of the fermi surface into small pockets with reduced doping. we argue that the incompressibility of the cu3d orbital and simultaneously the compressibility of the o2p orbital in the pseudogap state seems to be required to nucleate dynamic stripes.
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arxiv:1109.0463
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the daniel k. inouye solar telescope ( dkist ) visible spectro - polarimeter ( visp ) is a traditional slit - scanning spectrograph, with the ability to observe solar regions up to a $ 120 \ times78 ~ \ mathrm { arcsec } ^ 2 $ area. the design implements dual - beam polarimetry, a polychromatic polarization modulator, a high - dispersion echelle grating, and three spectral channels that can be automatically positioned. a defining feature of the instrument is its capability to tune anywhere within the 380 - 900 ~ nm range of the solar spectrum, allowing for a virtually infinite number of combinations of three wavelengths to be observed simultaneously. this enables the visp user to pursue well - established spectro - polarimetric studies of the magnetic structure and plasma dynamics of the solar atmosphere, as well as completely novel investigations of the solar spectrum. within the suite of first - generation instruments at the dkist, visp is the only wavelength - versatile spectro - polarimeter available to the scientific community. it was specifically designed to be a discovery instrument, for the exploration of new spectroscopic and polarimetric diagnostics, and to test improved models of polarized line formation, through high spatial -, spectral -, and temporal - resolution observations of the sun ' s polarized spectrum. in this instrument article, we describe the science requirements and design drivers of visp, and we present preliminary science data collected during the commissioning of the instrument.
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arxiv:2203.00117
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using a simple method to interpret the luminosity function of ly - alpha emitters, we explore properties of ly - alpha emitters from 5. 7 < z < 8. 8 with various assumptions about metallicity and stellar mass spectra. we constrain a mass - to - ' observed ' light ratio, m _ h / l _ band. for narrow - band surveys, l _ band is simply related to the intrinsic ly - alpha luminosity with a survival fraction of ly - alpha photons, alpha _ esc. the mass - to - ' bolometric light ', m _ h / l _ bol, can also be deduced, once the metallicity and stellar mass spectrum are given. the inferred m _ h / l _ bol is more sensitive to metallicity than to the mass spectrum. we find the following constraints on a mass - to - light ratio of ly - alpha emitters from 5. 7 < z < 7 : ( m _ h / l _ bol ) ( alpha _ { esc } epsilon ^ { 1 / gamma } ) ^ { - 1 } = 21 - 38, 14 - 26, and 9 - 17 for z = 0, 1 / 50, and 1 z _ sun, respectively, where epsilon is the ' duty cycle ' of ly - alpha emitters, and gamma ~ 2 is a local slope of the cumulative luminosity function. only weak lower limits are obtained for z = 8. 8. therefore, ly - alpha emitters are consistent with either starburst galaxies m _ h / l _ bol ~ 0. 1 - 1 with a smaller ly - alpha survival fraction, alpha _ { esc } epsilon ^ { 1 / gamma } ~ 0. 01 - 0. 05, or normal populations ( m _ h / l _ bol ~ 10 ) if a good fraction of ly - alpha photons survived, alpha _ { esc } epsilon ^ { 1 / gamma } ~ 0. 5 - 1. we find no evidence for the end of reionization in the luminosity functions of ly - alpha emitters discovered in the current ly - alpha surveys, including recent discovery of one ly - alpha emitter at z = 7. the data are consistent with no evolution of intrinsic properties of ly - alpha emitters or neutral fraction in the intergalactic medium up to z = 7. no detection of sources at z = 8. 8 does
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arxiv:0706.1801
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we introduce a method to compute particle detector transition probability in spacetime regions of general curved spacetimes provided that the curvature is not above a maximum threshold. in particular we use this method to compare the response of two detectors, one in a spherically symmetric gravitational field and the other one in rindler spacetime to compare the unruh and hawking effects : we study the vacuum response of a detector freely falling through a stationary cavity in a schwarzschild background as compared with the response of an equivalently accelerated detector traveling through an inertial cavity in the absence of curvature. we find that as we set the cavity in further radiuses from the black hole, the thermal radiation measured by the detector approaches the quantity recorded by the detector in rindler background showing in which way and at what scales the equivalent principle is recovered in the hawking - unruh effect. i. e. when the hawking effect in a schwarzschild background becomes equivalent to the unruh effect in rindler spacetime.
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arxiv:1310.5097
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so far, the relationship between open science and software engineering expertise has largely focused on the open release of software engineering research insights and reproducible artifacts, in the form of open - access papers, open data, and open - source tools and libraries. in this position paper, we draw attention to another perspective : scientific insight itself is a complex and collaborative artifact under continuous development and in need of continuous quality assurance, and as such, has many parallels to software artifacts. considering current calls for more open, collaborative and reproducible science ; increasing demands for public accountability on matters of scientific integrity and credibility ; methodological challenges coming with transdisciplinary science ; political and communication tensions when scientific insight on societally relevant topics is to be translated to policy ; and struggles to incentivize and reward academics who truly want to move into these directions beyond traditional publishing habits and cultures, we make the parallels between the emerging open science requirements and concepts already well - known in ( open - source ) software engineering research more explicit. we argue that the societal impact of software engineering expertise can reach far beyond the software engineering research community, and call upon the community members to pro - actively help driving the necessary systems and cultural changes towards more open and accountable research.
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arxiv:2302.05669
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we present a state - of - the - art image recognition system, deep image, developed using end - to - end deep learning. the key components are a custom - built supercomputer dedicated to deep learning, a highly optimized parallel algorithm using new strategies for data partitioning and communication, larger deep neural network models, novel data augmentation approaches, and usage of multi - scale high - resolution images. our method achieves excellent results on multiple challenging computer vision benchmarks.
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arxiv:1501.02876
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new tools have made it much easier for students to develop skills to work with interesting data sets as they begin to extract meaning from data. to fully appreciate the statistical analysis cycle, students benefit from repeated experiences collecting, ingesting, wrangling, analyzing data and communicating results. how can we bring such opportunities into the classroom? we describe a classroom activity, originally developed by danny kaplan ( macalester college ), in which students can expand upon statistical problem solving by hand - scraping data from cars. com, ingesting these data into r, then carrying out analyses of the relationships between price, mileage, and model year for a selected type of car.
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arxiv:1809.02952
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new data from hera experiment on ( diffractive ) deep inelastic scattering has been used to parameterize nucleon and pomeron structure functions. within the gribov theory, the parameterizations were employed to calculate gluon shadowing for various heavy ions and compared our results with predictions from other models. calculations for d + au collisions at forward rapidities at ultra - relativistic energies have been made and are compared to rhic data on the nuclear modification factor. results for gluon shadowing are also confronted with recent data on the nuclear modification factor at $ \ sqrt { s } = 17. 3 $ gev at various values of the feynman variable $ x _ f $, and the energy dependence of the effect is discussed.
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arxiv:hep-ph/0608003
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a general approach to find out exact cosmological solutions in f ( r ) - gravity is discussed. instead of taking into account phenomenological models, we assume, as a physical criterium, the existence of noether symmetries in the cosmological f ( r ) lagrangian. as a result, the presence of such symmetries selects viable models and allow to solve the equations of motion. we discuss also the case in which no noether charge is present but general criteria can be used to achieve solutions.
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arxiv:0804.2163
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soccer is a globally popular sporting event, typically characterized by long matches and distinctive highlight moments. recent advances in multimodal large language models ( mllms ) offer promising capabilities in temporal grounding and video understanding, soccer commentary generation often requires precise temporal localization and semantically rich descriptions over long - form video. however, existing soccer mllms often rely on the temporal a priori for caption generation, so they cannot process the soccer video end - to - end. while some traditional approaches follow a two - step paradigm that is complex and fails to capture the global context to achieve suboptimal performance. to solve the above issues, we present timesoccer, the first end - to - end soccer mllm for single - anchor dense video captioning ( sdvc ) in full - match soccer videos. timesoccer jointly predicts timestamps and generates captions in a single pass, enabling global context modeling across 45 - minute matches. to support long video understanding of soccer matches, we introduce mofa - select, a training - free, motion - aware frame compression module that adaptively selects representative frames via a coarse - to - fine strategy, and incorporates complementary training paradigms to strengthen the model ' s ability to handle long temporal sequences. extensive experiments demonstrate that our timesoccer achieves state - of - the - art ( sota ) performance on the sdvc task in an end - to - end form, generating high - quality commentary with accurate temporal alignment and strong semantic relevance.
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arxiv:2504.17365
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la ( fe, si ) $ _ { 13 } $ - based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. many studies have focused on this material family but only in bulk form. in this paper, we report the fabrication of thick films of la ( fe, si ) $ _ { 13 } $, both with and without post - hydriding. these films exhibit magnetic and structural properties comparable to those of bulk materials. we also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in the cases of other materials in which negative thermal hysteresis has been found. here, it appears that the substrate acts to store strain energy. our exploratory study demonstrates the viability of thick films of the la ( fe, si ) $ _ { 13 } $ phase and motivates further work in the area, while showing that additional perspectives can be gained from reducing the dimensionality of magnetocaloric materials in which the magneto - volume effect is large.
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arxiv:2006.01656
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we present a compilation of measurements of the stellar mass density as a function of redshift. using this stellar mass history we obtain a star formation history and compare it to the instantaneous star formation history. for z < 0. 7 there is good agreement between the two star formation histories. at higher redshifts the instantaneous indicators suggest star formation rates larger than that implied by the evolution of the stellar mass density. this discrepancy peaks at z = 3 where instantaneous indicators suggest a star formation rate around 0. 6 dex higher than those of the best fit to the stellar mass history. we discuss a variety of explanations for this inconsistency, such as inaccurate dust extinction corrections, incorrect measurements of stellar masses and a possible evolution of the stellar initial mass function.
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arxiv:0801.1594
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accurate and rapid detection of gait phases is of utmost importance in achieving optimal performance of powered lower - limb prostheses and exoskeletons. with the increasing versatility and complexity of these robotic systems, there is a growing need to enhance the performance of gait detection algorithms. the development of reliable and functional gait detection algorithms holds the potential to enhance precision, stability, and safety in prosthetic devices and other rehabilitation technologies. in this systematic review, we delve into the extensive body of research and development in the domain of gait event detection methods, with a specific focus on their application to prosthetic devices. our review critically assesses various proposed methods, aiming to identify the most effective approaches for gait phase classification in lower limb robotic systems. through a comprehensive comparative analysis, we highlight the strengths and weaknesses of different algorithms, shedding light on their performance characteristics, applicability, and potential for further improvements. this comprehensive review was conducted by screening two databases, namely ieee and scopus. the search was limited to 204 papers published from 2010 to 2023. a total of 6 papers that focused on heuristic, thresholding, and amplitude zero crossing involved techniques were identified and included in the review. 33. 3 % of implemented algorithms used kinematic parameters such as joint angles, joint linear and angular velocity, and joint angular acceleration. this study purely focuses on threshold - based algorithms and thus paper focusing on other gait phase detection methods were excluded.
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arxiv:2310.09733
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the first direct detection limits on dark matter in the mev to gev mass range are presented, using xenon10 data. such light dark matter can scatter with electrons, causing ionization of atoms in a detector target material and leading to single - or few - electron events. we use 15 kg - days of data acquired in 2006 to set limits on the dark - matter - electron scattering cross section. the strongest bound is obtained at 100 mev where sigma _ e < 3 x 10 ^ { - 38 } cm ^ 2 at 90 % cl, while dark matter masses between 20 mev and 1 gev are bounded by sigma _ e < 10 ^ { - 37 } cm ^ 2 at 90 % cl. this analysis provides a first proof - of - principle that direct detection experiments can be sensitive to dark matter candidates with masses well below the gev scale.
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arxiv:1206.2644
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we consider diffusion caused by a combined influence of the hall effect and electric currents, and argue that such diffusion forms chemical inhomogeneities in plasma. the considered mechanism can be responsible for the formation of element spots in laboratory and astrophysical plasmas. such current - driven diffusion can be accompanied by the propagation of a particular type of waves which have not been considered earlier. in these waves, the impurity number density oscillare alone and their frequency is determined by the electric currents and sort of impurity ions. these compositional waves exist if the magnetic pressure in plasma is much greater than the gas pressure. such waves lead to local variations of chemical composition and, hence, can manifest themselves by variations of the emission in spectral lines.
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arxiv:1605.07893
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a search for the $ k ^ { + } \ to \ pi ^ { 0 } \ pi ^ { 0 } \ pi ^ { 0 } e ^ + \ nu $ decay is performed by the oka collaboration. the search is based on $ 3. 65 \ times 10 ^ 9 ~ k ^ + $ decays. no signal is observed. the upper limit set is $ br ( k ^ { + } \ to \ pi ^ { 0 } \ pi ^ { 0 } \ pi ^ { 0 } e ^ + \ nu ) < 5. 4 \ times 10 ^ { - 8 } ~ 90 \ % $ cl, 65 times lower than the one currently listed by pdg.
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arxiv:2409.08817
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we prove that a linear fractional operator with an asymptotically constant lower order term in the whole space admits eigenvalues.
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arxiv:1506.05697
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we compile a list of 2 - d and axisymmetric green ' s functions for isotropic full and half spaces, to complement our letter " linear elasticity of incompressible solids ". we also extend the isotropic exactly incompressible linear theory from our letter to include isotropic neo - hookean solids subject to a large pre - strain, and present green ' s functions in these cases. the green ' s function for a pre - strained half - space reproduces the biot instability.
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arxiv:1407.1405
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using hf + bcs method we study light nuclei with nuclear charge in the range $ 2 \ leq z \ leq 8 $ and lying near the neutron drip line. the hf method uses effective skyrme forces and allows for axial deformations. we find that the neutron drip line forms stability peninsulas at $ ^ { 18 } $ he and $ ^ { 40 } $ c. these isotopes are found to be stable against one neutron emission and possess the highest known neutron to proton ratio in stable nuclei.
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arxiv:1504.03876
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the solow - swan model is shortly reviewed from a mathematical point of view. by considering non - constant returns to scale, we obtain a general solution strategy. we then compute the exact solution for the cobb - douglas production function, for both the classical model and the von bertalanffy model. numerical simulations are provided.
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arxiv:2008.05875
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we prove a linearization result for quasistatic fracture evolution in nonlinear elasticity. as the stiffness of the material tends to infinity, we show that rescaled displacement fields and their associated crack sets converge to a solution of quasistatic crack growth in linear elasticity without any a priori assumptions on the geometry of the crack set. this result corresponds to the evolutionary counterpart of the static linearization result by the first author, where a griffith model for nonsimple brittle materials has been considered featuring an elastic energy which also depends suitably on the second gradient of the deformations. the proof relies on a careful study of unilateral global minimality, as determined by the nonlinear evolutionary problem, and its linearization together with a variant of the jump transfer lemma in gsbd.
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arxiv:2411.13446
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we present a family of localized radiation modes in multilayered periodic media, where in - phase superposition of p - polarized waves leads to radiative confinement around the beam axis. excitation of surface plasmon polaritons yields an enhanced localization normally to the interfaces. on the other hand, the spectral filtering induced by the presence of bandgaps allows to achieve transverse superresolution on the interfaces. subwavelength beamwidths along an infinitely long distance might potentially be obtained.
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arxiv:1001.3204
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we solve the open question of the existence of four - qubit entangled symmetric states with positive partial transpositions ( ppt states ). we reach this goal with two different approaches. first, we propose a half - analytical - half - numerical method that allows to construct multipartite ppt entangled symmetric states ( pptess ) from the qubit - qudit ppt entangled states. second, we adapt the algorithm allowing to search for extremal elements in the convex set of bipartite ppt states [ j. m. leinaas, j. myrheim, and e. ovrum, phys. rev. a 76, 034304 ( 2007 ) ] to the multipartite scenario. with its aid we search for extremal four - qubit pptess and show that generically they have ranks ( 5, 7, 8 ). finally, we provide an exhaustive characterization of these states with respect to their separability properties.
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arxiv:1203.3711
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we prove the intrinsic harnack ' s inequality for a general form of a parabolic equation that generalizes both the standard parabolic $ p $ - laplace equation and the normalized version arising from stochastic game theory. we prove each result for the optimal range of exponents and ensure that we get stable constants.
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arxiv:2308.13443
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during active learning, an effective stopping method allows users to limit the number of annotations, which is cost effective. in this paper, a new stopping method called predicted change of f measure will be introduced that attempts to provide the users an estimate of how much performance of the model is changing at each iteration. this stopping method can be applied with any base learner. this method is useful for reducing the data annotation bottleneck encountered when building text classification systems.
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arxiv:1901.09118
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in this paper, we propose a global digital platform to avoid and combat epidemics by providing relevant real - time information to support selective lockdowns. it leverages the pervasiveness of wireless connectivity while being trustworthy and secure. the proposed system is conceptualized to be decentralized yet federated, based on ubiquitous public systems and active citizen participation. its foundations lie on the principle of informational self - determination. we argue that only in this way it can become a trustworthy and legitimate public good infrastructure for citizens by balancing the asymmetry of the different hierarchical levels within the federated organization while providing highly effective detection and guiding mitigation measures towards graceful lockdown of the society. to exemplify the proposed system, we choose the remote patient monitoring as use case. in which, the integration of distributed ledger technologies with narrowband iot technology is evaluated considering different number of endorsed peers. an experimental proof of concept setup is used to evaluate the performance of this integration, in which the end - to - end latency is slightly increased when a new endorsed element is added. however, the system reliability, privacy, and interoperability are guaranteed. in this sense, we expect active participation of empowered citizens to supplement the more usual top - down management of epidemics.
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arxiv:2010.13392
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the quadratic computational complexity of the attention mechanism in current large language models ( llms ) renders inference with long contexts prohibitively expensive. to address this challenge, various approaches aim to retain critical portions of the context to optimally approximate full attention ( fa ) through key - value ( kv ) compression or sparse attention ( sa ), enabling the processing of virtually unlimited text lengths in a streaming manner. however, these methods struggle to achieve performance levels comparable to fa, particularly in retrieval tasks. in this paper, our analysis of attention head patterns reveals that llms ' attention distributions show strong local correlations, naturally reflecting a chunking mechanism for input context. we propose ltri - llm framework, which divides kvs into spans, stores them in an offline index, and retrieves the relevant kvs into memory for various queries. experimental results on popular long text benchmarks show that ltri - llm can achieve performance close to fa while maintaining efficient, streaming - based inference.
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arxiv:2412.04757
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star - forming galaxies are considered to be the leading candidate sources that dominate the cosmic reionization at z > 7, and the search for analogs at moderate redshift showing lyman continuum ( lyc ) leakage is currently a active line of research. we have observed a star - forming galaxy at z = 3. 2 with hubble / wfc3 in the f336w filter, corresponding to the 730 - 890a rest - frame, and detect lyc emission. this galaxy is very compact and also has large oxygen ratio [ oiii ] 5007 / [ oii ] 3727 ( > = 10 ). no nuclear activity is revealed from optical / near - infrared spectroscopy and deep multi - band photometry ( including the 6ms x - ray, chandra ). the measured escape fraction of ionizing radiation spans the range 50 - 100 \ %, depending on the igm attenuation. the lyc emission is detected at s / n = 10 with m ( f336w ) = 27. 57 + / - 0. 11 and it is spatially unresolved, with effective radius r _ e < 200pc. predictions from photoionization and radiative transfer models are in line with the properties reported here, indicating that stellar winds and supernova explosions in a nucleated star - forming region can blow cavities generating density - bounded conditions compatible with optically thin media. irrespective to the nature of the ionizing radiation, spectral signatures of these sources over the entire electromagnetic spectrum are of central importance for their identification during the epoch of reionization, when the lyc is unobservable. intriguingly, the spitzer / irac photometric signature of intense rest - frame optical emissions ( [ oiii ] + hbeta ) observed recently at z ~ 7. 5 - 8. 5 is similar to what is observed in this galaxy. only the james webb space telescope will measure optical line ratios at z > 7 allowing a direct comparison with lower redshift lyc emitters, as reported here.
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arxiv:1602.00688
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we present the path - integral solutions to the distributions in classical ( gibbs ) and quantum ( wigner ) statistical mechanics. the kernel of the distributions are derived in two ways - one by time slicing and defining the appropriate short - time interval phase space matrix element and second by making use of the kernel in the path - integral approach to quantum mechanics. we show that the two approaches are perturbatively identical. we also present another computation for the wigner kernel, which is also the liouville kernel, for the harmonic oscillator and free particle. these kernels may be used as the starting point in the perturbative expansion of the wigner kernel for any potential. with the kernel solved, we essentially solve also the distributions in classical and quantum statistical mechanics.
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arxiv:1608.06280
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geodesic distances on manifolds have numerous applications in image processing, computer graphics and computer vision. in this work, we introduce an approach called ` lggd ' ( learned generalized geodesic distances ). this method involves generating node features by learning a generalized geodesic distance function through a training pipeline that incorporates training data, graph topology and the node content features. the strength of this method lies in the proven robustness of the generalized geodesic distances to noise and outliers. our contributions encompass improved performance in node classification tasks, competitive results with state - of - the - art methods on real - world graph datasets, the demonstration of the learnability of parameters within the generalized geodesic equation on graph, and dynamic inclusion of new labels.
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arxiv:2407.01194
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reliably predicting the geomorphology and climate of planetary bodies requires knowledge of the dynamic threshold wind shear velocity below which saltation transport ceases. here we measure this threshold in a wind tunnel for four well - sorted and two poorly sorted sand beds by visual means and by a method that exploits a regime shift in the behavior of the surface roughness caused by momentum transfer from the wind to the saltating particles. for our poorly sorted sands, we find that these measurement methods yield different threshold values because, at the smaller visual threshold, relatively coarse particles do not participate in saltation. we further find that both methods yield threshold values that are much larger ( 60 - - 250 \ % ) for our poorly sorted sands than for our well - sorted sands with similar median particle diameter. in particular, even a rescaling of the dynamic saltation threshold based on the 90th percentile particle diameter rather than the median diameter cannot fully capture this difference, suggesting that relatively very coarse particles have a considerable control on the dynamic threshold. similar findings were previously reported for water - driven sediment transport. our findings have important implications for quantitative predictions of saltation transport - related geophysical processes, such as dust aerosol emission.
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arxiv:1909.00132
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a measurement of the 21 - cm global signal would be a revealing probe of the dark ages, the era of first star formation, and the epoch of reionization. it has remained elusive owing to bright galactic and extra - galactic foreground contaminants, coupled with instrumental noise, ionospheric effects, and beam chromaticity. the simultaneous detection of a consistent 21 - cm dipole signal alongside the 21 - cm global signal would provide confidence in a claimed detection. we use simulated data to investigate the possibility of using drift - scan dipole antenna experiments to achieve a detection of both monopole and dipole. we find that at least two antennae located at different latitudes are required to localise the dipole. in the absence of foregrounds, a total integration time of $ \ sim 10 ^ 4 $ hours is required to detect the dipole. with contamination by simple foregrounds, we find that the integration time required increases to $ \ sim 10 ^ 5 $ hours. we show that the extraction of the 21 - cm dipole from more realistic foregrounds requires a more sophisticated foreground modelling approach. finally, we motivate a global network of dipole antennae that could reasonably detect the dipole in $ \ sim 10 ^ 3 $ hours of integration time.
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arxiv:2310.06063
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the sample compression conjecture of littlestone & warmuth has remained unsolved for over two decades. this paper presents a systematic geometric investigation of the compression of finite maximum concept classes. simple arrangements of hyperplanes in hyperbolic space, and piecewise - linear hyperplane arrangements, are shown to represent maximum classes, generalizing the corresponding euclidean result. a main result is that pl arrangements can be swept by a moving hyperplane to unlabeled d - compress any finite maximum class, forming a peeling scheme as conjectured by kuzmin & warmuth. a corollary is that some d - maximal classes cannot be embedded into any maximum class of vc dimension d + k, for any constant k. the construction of the pl sweeping involves pachner moves on the one - inclusion graph, corresponding to moves of a hyperplane across the intersection of d other hyperplanes. this extends the well known pachner moves for triangulations to cubical complexes.
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arxiv:0911.3633
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we employ nonlinear autocorrelation measurements to investigate plasmon - assisted hot carrier dynamics generated in optical gold antennas. we demonstrate that surface plasmons enable a nonlinear formation of hot carriers, providing thus a unique lever to optimize the energy distribution and generation efficiency of the photo - excited charges. the temporal response of the carriers ' relaxation can be controlled within a range extending from 500 ~ fs to 2. 5 ~ ps. by conducting a quantitative analysis of the dynamics, we determine the nonlinear absorption cross - section of individual optical antennas. as such, this work provides strong insights on the understanding of plasmon - induced hot carrier generation, especially in the view of applications where the time response plays a preponderant role.
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arxiv:1601.02779
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experiences with the implementation of strong gr \ " obner bases respectively standard bases for polynomial rings over principal ideal rings are explained : different strategies for creating the pair set, methods to avoid coefficient growth and a normal form algorithm for non - global orderings.
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arxiv:1609.04257
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we present a velocimetric and spectropolarimetric analysis of 27 observations of the 22 - myr m1 star au microscopii ( au mic ) collected with the high - resolution $ yjhk $ ( 0. 98 - 2. 35 $ \ mu $ m ) spectropolarimeter spirou from 2019 september 18 to november 14. our radial velocity ( rv ) time - series exhibits activity - induced fluctuations of 45 m / s rms, about three times smaller than those measured in the optical domain, that we filter using gaussian process regression. we report a 3. 9 $ \ sigma $ - detection of the recently - discovered 8. 46 - d transiting planet au mic b, with an estimated mass of $ 17. 1 ^ { + 4. 7 } _ { - 4. 5 } $ m $ _ { \ odot } $ and a bulk density of $ 1. 3 \ pm 0. 4 $ g / cm $ ^ { - 3 } $, inducing a rv signature of semi - amplitude $ k = 8. 5 ^ { + 2. 3 } _ { - 2. 2 } $ m / s in the spectrum of its host star. a consistent detection is independently obtained when we simultaneously image stellar surface inhomogeneities and estimate the planet parameters with zeeman - doppler imaging ( zdi ). using zdi, we invert the time series of unpolarized and circularly - polarized spectra into surface brightness and large - scale magnetic maps. we find a mainly poloidal and axisymmetric field of 475 g, featuring, in particular, a dipole of 450 g tilted at 19 { \ deg } to the rotation axis. moreover, we detect a strong differential rotation of d $ \ omega = 0. 167 \ pm 0. 009 $ rad / d shearing the large - scale field, about twice stronger than that shearing the brightness distribution, suggesting that both observables probe different layers of the convective zone. even though we caution that more rv measurements are needed to accurately pin down the planet mass, au mic b already appears as a prime target for constraining planet formation models, studying the interactions with the surrounding debris disk, and characterizing its atmosphere with upcoming space - and ground - based missions.
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arxiv:2011.13357
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certain axiomatic notions of $ \ textit { affine space } $ over a ring and $ \ textit { convex space } $ over a preordered ring are examples of the notion of $ \ mathcal { t } $ - algebra for an algebraic theory $ \ mathcal { t } $ in the sense of lawvere. herein we study the notion of $ \ textit { commutant } $ for lawvere theories that was defined by wraith and generalizes the notion of $ \ textit { centralizer clone } $. we focus on the lawvere theory of $ \ textit { left $ r $ - affine spaces } $ for a ring or rig $ r $, proving that this theory can be described as a commutant of the theory of pointed right $ r $ - modules. further, we show that for a wide class of rigs $ r $ that includes all rings, these theories are commutants of one another in the full finitary theory of $ r $ in the category of sets. we define $ \ textit { left $ r $ - convex spaces } $ for a preordered ring $ r $ as left affine spaces over the positive part $ r _ + $ of $ r $. we show that for any $ \ textit { firmly archimedean } $ preordered algebra $ r $ over the dyadic rationals, the theories of left $ r $ - convex spaces and pointed right $ r _ + $ - modules are commutants of one another within the full finitary theory of $ r _ + $ in the category of sets. applied to the ring of real numbers $ \ mathbb { r } $, this result shows that the connection between convex spaces and pointed $ \ mathbb { r } _ + $ - modules that is implicit in the integral representation of probability measures is a perfect ` duality ' of algebraic theories.
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arxiv:1603.03351
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in this paper, we consider the problem of determining the \ emph { exact } number of periodic orbits for polynomial planar flows. this problem is a variant of hilbert ' s 16th problem. using a natural definition of computability, we show that the problem is noncomputable on the one hand and, on the other hand, computable uniformly on the set of all structurally stable systems defined on the unit disk. we also prove that there is a family of polynomial planar systems which does not have a computable sharp upper bound on the number of its periodic orbits.
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arxiv:2101.07701
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we review the effective field theory associated with the superfluid phonons that we use for the study of transport properties in the core of superfluid neutrons stars in their low temperature regime. we then discuss the shear and bulk viscosities together with the thermal conductivity coming from the collisions of superfluid phonons in neutron stars. with regard to shear, bulk, and thermal transport coefficients, the phonon collisional processes are obtained in terms of the equation of state and the superfluid gap. we compare the shear coefficient due to the interaction among superfluid phonons with other dominant processes in neutron stars, such as electron collisions. we also analyze the possible consequences for the r - mode instability in neutron stars. as for the bulk viscosities, we determine that phonon collisions contribute decisively to the bulk viscosities inside neutron stars. for the thermal conductivity resulting from phonon collisions, we find that it is temperature independent well below the transition temperature. we also obtain that the thermal conductivity due to superfluid phonons dominates over the one resulting from electron - muon interactions once phonons are in the hydrodynamic regime. as the phonons couple to the $ z $ electroweak gauge boson, we estimate the associated neutrino emissivity. we also briefly comment on how the superfluid phonon interactions are modified in the presence of a gravitational field or in a moving background.
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arxiv:2101.09000
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recently, there has been growing attention on behalf of both academic and practice communities towards the ability of artificial intelligence ( ai ) systems to operate responsibly and ethically. as a result, a plethora of frameworks and guidelines have appeared to support practitioners in implementing trustworthy ai applications ( tai ). however, little research has been done to investigate whether such frameworks are being used and how. in this work, we study the vision ai practitioners have on tai principles, how they address them, and what they would like to have - in terms of tools, knowledge, or guidelines - when they attempt to incorporate such principles into the systems they develop. through a survey and semi - structured interviews, we systematically investigated practitioners ' challenges and needs in developing tai systems. based on these practical findings, we highlight recommendations to help ai practitioners develop trustworthy ai applications.
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arxiv:2407.12135
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charge transport in disordered organic semiconductors occurs by hopping of charge carriers between localized sites that are randomly distributed in a strongly energy dependent density of states. extracting disorder and hopping parameters from experimental data like temperature dependent current - voltage characteristics typically relies on parametrized mobility functionals that are integrated in a drift - diffusion solver. surprisingly, the functional based on the extended gaussian disorder model ( egdm ) has been extremely successful at this, despite it being based on the assumption of nearest neighbor hopping ( nnh ) on a regular lattice. we here propose a variable range hopping ( vrh ) model that has been integrated in a freeware drift - diffusion solver. the mobility model has been calibrated using kinetic monte carlo calculations and shows good agreement with the monte carlo calculations over the experimentally relevant part of the parameter space. the model is applied to temperature - dependent space charge limited current ( sclc ) measurements of different systems. in contrast to the egdm, the vrh model provides a consistent description of both p - type and n - type devices. we find a critical ratio of ann / $ \ alpha $ ( mean inter - site distance / localization radius ) of ~ 3 below which hopping to non - nearest neighbors becomes important around room temperature and the egdm cannot be used for parameter extraction. typical ( gaussian ) disorder values in the range 45 - 120 mev are found, without any clear correlation with photovoltaic performance when the same active layer is used in an organic solar cell.
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arxiv:2103.03856
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although polygon meshes have been a standard representation in geometry processing, their irregular and combinatorial nature hinders their suitability for learning - based applications. in this work, we introduce a novel learnable mesh representation through a set of local 3d sample points and their associated normals and quadric error metrics ( qem ) w. r. t. the underlying shape, which we denote ponq. a global mesh is directly derived from ponq by efficiently leveraging the knowledge of the local quadric errors. besides marking the first use of qem within a neural shape representation, our contribution guarantees both topological and geometrical properties by ensuring that a ponq mesh does not self - intersect and is always the boundary of a volume. notably, our representation does not rely on a regular grid, is supervised directly by the target surface alone, and also handles open surfaces with boundaries and / or sharp features. we demonstrate the efficacy of ponq through a learning - based mesh prediction from sdf grids and show that our method surpasses recent state - of - the - art techniques in terms of both surface and edge - based metrics.
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arxiv:2403.12870
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in this paper we study the molecular gas content of a representative sample of 67 of the most massive early - type galaxies in the local universe, drawn uniformly from the massive survey. we present new iram - 30m telescope observations of 30 of these galaxies, allowing us to probe the molecular gas content of the entire sample to a fixed molecular - to - stellar mass fraction of 0. 1 %. the total detection rate in this representative sample is 25 $ ^ { + 5. 9 } _ { - 4. 4 } $ %, and by combining the massive and atlas $ ^ { \ rm 3d } $ molecular gas surveys we find a joint detection rate of 22. 4 $ ^ { + 2. 4 } _ { - 2. 1 } $ %. this detection rate seems to be independent of galaxy mass, size, position on the fundamental plane, and local environment. we show here for the first time that true slow rotators can host molecular gas reservoirs, but the rate at which they do so is significantly lower than for fast - rotators. objects with a higher velocity dispersion at fixed mass ( a higher kinematic bulge fraction ) are less likely to have detectable molecular gas, and where gas does exist, have lower molecular gas fractions. in addition, satellite galaxies in dense environments have $ \ approx $ 0. 6 dex lower molecular gas - to - stellar mass ratios than isolated objects. in order to interpret these results we created a toy model, which we use to constrain the origin of the gas in these systems. we are able to derive an independent estimate of the gas - rich merger rate in the low - redshift universe. these gas rich mergers appear to dominate the supply of gas to etgs, but stellar mass loss, hot halo cooling and transformation of spiral galaxies also play a secondary role.
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arxiv:1903.08884
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for $ g = { \ rm gl } ( n, q ) $, the proportion $ p _ { n, q } $ of pairs $ ( \ chi, g ) $ in $ { \ rm irr } ( g ) \ times g $ with $ \ chi ( g ) \ neq 0 $ satisfies $ p _ { n, q } \ to 0 $ as $ n \ to \ infty $.
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arxiv:1909.01111
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densely - packed, all - digital aperture arrays form a key area of technology development required for the square kilometre array ( ska ) radio telescope. the design of real - time signal processing systems for digital aperture arrays is currently a central challenge in pathfinder projects worldwide. we describe interim results of such work ; an heirarchical, frequency - domain beamforming architecture for synthesising a sky beam from the wideband antenna feeds of digital aperture arrays.
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arxiv:0910.2865
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recent analyses suggest that in tev scales that will be made accessible at the lhc copious amounts of color scalar parton bound states may be produced. would this be the case, the scalars would leave long enough to interact and this could lead to new physics. these interaction could be direct, but also take place with a mediation of the dense parton medium through which they propagate. since multiple processes would have to be included, the latter case is too convoluted to be treated with perturbative methods applied to the standard model. we explore a possibility of describing such interaction by a nonlocal lagrangian which is an infinite polynomial in the field variables, momentum and mass. we treat all scalars as identical, use a o ( n ) - symmetric lagrangian, where n is the number of scalars and discuss the problem in 1 / n expansion. nonrenormalizable by all traditional criteria, such model still requires only a limited set of multiplicative renormalizations, provided that the parameters in the lagrangian are not treated as an infinite set of independent coupling constants, but as finite expansion coefficients of the lagrangian in powers of field variables, mass and momenta. the necessary constraints on the relative magnitudes of these coefficients can be determined order by order in a double series in the single coupling constant and 1 / n.
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arxiv:0910.5506
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lagrangian displacement field $ \ psi $ is the central object in lagrangian perturbation theory ( lpt ). lpt is very successful at high redshifts, but it performs poorly at low redshifts due to severe shell crossing. to understand and quantify the effects of shell crossing, we extract $ \ psi $ from n - body simulation and decompose it into scalar and vector parts. we find that at late time the power spectrum of the scalar part agrees with 1 - loop results from lpt at large scales, while the power in small scales is much suppressed due to shell crossing. at z = 0, the power spectrum of $ \ psi $ is 10 % lower than the 1 - loop results at k = 0. 1 h / mpc. shell crossing also generates the vector contribution in $ \ psi $, although its effect is subdominant in comparison with the power suppression in the scalar part. at z = 0, the vector part contributes 10 % to the total power spectrum of $ \ psi $ at k = 1 h / mpc, while only 1 % is expected from the vector contribution in lpt. we also examine the standard lpt recipes and some of its variants. in one of the variants, we include a power suppression factor in the displacement potential to take into account the power suppression in small scales after shell crossing. however, these simple phenomenological approaches are found to yield limited improvement compared to the standard lpt after the onset of shell crossing.
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arxiv:1309.2243
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the development of powerful infrared observational technics enables the study of very extincted objects and young embedded star forming regions. this is especially interesting in the context of massive stars which form and spend a non negligible fraction of their life still enshrouded in their parental molecular cloud. spectrophotometric calibrations are thus necessary to constrain the physical properties of heavily extincted objects. here, we derive ubvjhk magnitudes and bolometric corrections from a grid of atmosphere models for o stars. bessel passbands are used. bolometric corrections ( bc ) are derived as a function of teff and are subsequently used to derive bc - spectral type ( st ) and absolute magnitudes - st relations. infrared magnitudes and, for the first time, bolometric corrections are given for the full range of spectral types and luminosity classes. infrared colors are essentially constant. intrinsic h - k colors are 0. 05 mag bluer than previously proposed. optical calibrations are also provided and are similar to previous work, except for ( b - v ) 0 which is found to be at minimum - 0. 28 for standard o stars, slightly larger ( 0. 04 mag ) than commonly accepted.
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arxiv:astro-ph/0606587
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harmonic inversion has already been proven to be a powerful tool for the analysis of quantum spectra and the periodic orbit orbit quantization of chaotic systems. the harmonic inversion technique circumvents the convergence problems of the periodic orbit sum and the uncertainty principle of the usual fourier analysis, thus yielding results of high resolution and high precision. based on the close analogy between periodic orbit trace formulae for regular and chaotic systems the technique is generalized in this paper for the semiclassical quantization of integrable systems. thus, harmonic inversion is shown to be a universal tool which can be applied to a wide range of physical systems. the method is further generalized in two directions : firstly, the periodic orbit quantization will be extended to include higher order hbar corrections to the periodic orbit sum. secondly, the use of cross - correlated periodic orbit sums allows us to significantly reduce the required number of orbits for semiclassical quantization, i. e., to improve the efficiency of the semiclassical method. as a representative of regular systems, we choose the circle billiard, whose periodic orbits and quantum eigenvalues can easily be obtained.
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arxiv:nlin/0005045
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verifying temporal compliance rules, such as a rule stating that an inquiry must be answered within a time limit, is a recurrent operation in the realm of business process compliance. in this setting, a typical use case is one where a manager seeks to retrieve all cases where a temporal rule is violated, given an event log recording the execution of a process over a time period. existing approaches for checking temporal rules require a full scan of the log. such approaches are unsuitable for interactive use when the log is large and the set of compliance rules is evolving. this paper proposes an approach to evaluate temporal compliance rules in sublinear time by pre - computing a data structure that summarizes the temporal relations between activities in a log. the approach caters for a wide range of temporal compliance patterns and supports incremental updates. our evaluation on twenty real - life logs shows that our data structure allows for real - time checking of a large set of compliance rules.
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arxiv:2112.04623
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shearlet systems have so far been only considered as a means to analyze $ l ^ 2 $ - functions defined on $ \ r ^ 2 $, which exhibit curvilinear singularities. however, in applications such as image processing or numerical solvers of partial differential equations the function to be analyzed or efficiently encoded is typically defined on a non - rectangular shaped bounded domain. motivated by these applications, in this paper, we first introduce a novel model for cartoon - like images defined on a bounded domain. we then prove that compactly supported shearlet frames satisfying some weak decay and smoothness conditions, when orthogonally projected onto the bounded domain, do provide ( almost ) optimally sparse approximations of elements belonging to this model class.
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arxiv:1007.3039
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pairs of radio emitting jets with lengths up to several hundred kiloparsecs emanate from the central region ( the ` core ' ) of radio loud active galaxies. in the most powerful of them, these jets terminate in the ` hotspots ', compact high brightness regions, where the jet flow collides with the intergalactic medium ( igm ). although it has long been established that in their inner ( $ \ sim $ parsec ) regions these jet flows are relativistic, it is still not clear if they remain so at their largest ( hundreds of kiloparsec ) scales. we argue that the x - ray, optical and radio data of the hotspots, despite their at - first - sight disparate properties, can be unified in a scheme involving a relativistic flow upstream of the hotspot that decelerates to the sub - relativistic speed of its inferred advance through the igm and viewed at different angles to its direction of motion. this scheme, besides providing an account of the hotspot spectral properties with jet orientation, it also suggests that the large - scale jets remain relativistic all the way to the hotspots.
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arxiv:astro-ph/0304256
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we have focused on the topological structure of cubic string field theory ( csft ). from the similarity of action between csft and chern - simons ( cs ) theory in three dimensions, we have investigated the quantity $ { \ cal n } = \ pi ^ 2 / 3 \ int ( uqu ^ { - 1 } ) ^ 3 $, which is expected to be the counterpart of winding number in cs theory. in our previous research, it was reported that $ \ cal n $ can only take a limited number of integer values due to the inevitable anomalies in okawa type solution. to overcome this unsatisfactory results, we evaluate $ \ cal n $ and eom against a solution itself, $ \ cal t $, for more general class of pure gauge form solution written in $ k, b $ and $ c $ in this paper. then we obtain general formula of $ \ cal n $ and $ \ cal t $. from this result, we show that there is an infinite number of solutions that $ \ cal n $ takes any integer value while keeping $ \ cal t = 0 $. we also show the gauge invariant observable of these solutions take appropriate values. furthermore, we evaluate the integral form of the brst - exact quantity as surface integral.
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arxiv:1912.13487
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we classify all cubic extensions of any field of arbitrary characteristic, up to isomorphism, via an explicit construction involving three fundamental types of cubic forms. we deduce a classification of any galois cubic extension of a field. the splitting and ramification of places in a separable cubic extension of any global function field are completely determined, and precise riemann - hurwitz formulae are given. in doing so, we determine the decomposition of any cubic polynomial over a finite field.
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arxiv:1703.06219
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it is shown that the weak $ l ^ p $ spaces $ \ ell ^ { p, \ infty }, l ^ { p, \ infty } [ 0, 1 ] $, and $ l ^ { p, \ infty } [ 0, \ infty ) $ are isomorphic as banach spaces.
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arxiv:math/9201237
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in this paper, we introduced a generalization of the derived category, which is called the $ n $ - derived category and denoted by $ \ d _ { n } ( r ) $, of a given ring $ r $ for each $ n \ in \ mathbb { n } \ cup \ { \ infty \ } $. the $ n $ - derived category of a ring is proved to be very closely connected with its left little finitistic dimension. we also introduce and investigate the notions of $ n $ - exact sequences, $ n $ - projective ( resp., $ n $ - injective ) modules and $ n $ - exact complexes. in particular, we characterize the left little finitistic dimensions in terms of all above notions. finally, we build a connection of the classical derived categories and $ n $ - derived categories.
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arxiv:2306.09140
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we determine the kodaira dimension of the moduli space of even spin curves for all genera, with one possible exception : the scheme s _ g has negative kodaira dimension for g < 8 and it is of general type for g > 8. the kodaira dimension of s _ 8 is non - negative.
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arxiv:0805.2424
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we present an exact solution for a catalytically - activated annihilation a + a \ to 0 reaction taking place on a one - dimensional chain in which some segments ( placed at random, with mean concentration p ) possess special, catalytic properties. annihilation reaction takes place, as soon as any two a particles land from the reservoir onto two vacant sites at the extremities of the catalytic segment, or when any a particle lands onto a vacant site on a catalytic segment while the site at the other extremity of this segment is already occupied by another a particle. we find that the disorder - average pressure $ p ^ { ( quen ) } $ per site of such a chain is given by $ p ^ { ( quen ) } = p ^ { ( lan ) } + \ beta ^ { - 1 } f $, where $ p ^ { ( lan ) } = \ beta ^ { - 1 } \ ln ( 1 + z ) $ is the langmuir adsorption pressure, ( z being the activity and \ beta ^ { - 1 } - the temperature ), while $ \ beta ^ { - 1 } f $ is the reaction - induced contribution, which can be expressed, under appropriate change of notations, as the lyapunov exponent for the product of 2 \ times 2 random matrices, obtained exactly by derrida and hilhorst ( j. phys. a { \ bf 16 }, 2641 ( 1983 ) ). explicit asymptotic formulae for the particle mean density and the compressibility are also presented.
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arxiv:cond-mat/0209656
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