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in this paper, we investigate one - loop radiative corrections to the casimir energy in the presence of two perfectly conducting parallel plates for qed theory within the renormalized perturbation theory. in fact, there are three contributions for radiative corrections to the casimir energy, up to order $ \ alpha $. only the two - loop diagram, which is of order $ \ alpha $, has been computed by bordag et. al ( 1985 ), approximately. here, up to this order, we consider corrections due to two one - loop terms, i. e., photonic and fermionic loop corrections resulting from renormalized qed lagrangian, more precisely. our results show that only the fermionic loop has a very minor correction and the correction of photonic loop vanishes.
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arxiv:1212.4122
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recently, tiwari, chaubey, & pandey ( 2007 ) detected the bright component of the visual binary hd151878 to exhibit rapid photometric oscillations through a johnson b filter with a period of 6 min ( 2. 78 mhz ) and a high, modulated amplitude up to 22 mmag peak - to - peak, making this star by far the highest amplitude roap star known. as a new roap star, hd151878 is of additional particular interest as a scarce example of the class in the northern sky, and only the second known case of an evolved roap star - the other being hd 116114. we used the fies spectrograph at the nordic optical telescope to obtain high time resolution spectra at high dispersion to attempt to verify the rapid oscillations. we show here that the star at this epoch is spectroscopically stable to rapid oscillations of no more than a few tens of m / s. the high - resolution spectra furthermore show the star to be of type am rather than ap and we show the star lacks most of the known characteristics for rapidly oscillating ap stars. we conclude that this is an am star that does not pulsate with a 6 - min period. the original discovery of pulsation is likely to be an instrumental artefact.
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arxiv:0807.2821
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we study transitive partially hyperbolic diffeomorphisms in dimension 3 preserving a center foliation on which they act quasi - isometrically. we show that the diffeomorphism is up to finite lift and iterate, either a skew - product or a discretised anosov flow.
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arxiv:2411.10875
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the vastness of the space of possible multicomponent metal alloys is hoped to provide improved structural materials but also challenges traditional, low - throughput materials design efforts. computational screening could narrow this search space if models for materials stability and desired properties exist that are sufficiently inexpensive and accurate to efficiently guide experiments. towards this effort, here we develop a method to rapidly assess the thermodynamic stability of a metal alloy composition of arbitrary number of elements, stoichiometry, and temperature based on density functional theory ( dft ) data. in our model, the gibbs free energy of the solid solution contains binary enthalpy contributions and ideal configurational entropy, whereas only enthalpy is considered for intermetallic competing phases. compared to a past model for predicting the formation of single - phase high - entropy alloys [ phys. rev. x 5, 011041 ( 2015 ) ], our method is similarly inexpensive, since it assesses enthalpies based on existing dft data, but less heuristic, more broadly applicable, and more accurate ( 70 - - 75 % ) compared to experiment.
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arxiv:2309.12222
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a simple approximate solution to the linear response equations of time - dependent density functional theory ( tddft ) is given. this extends the single - pole approximation ( spa ) to two strongly - coupled poles. the analysis provides both an illustration of how tddft works when strong exchange - correlation effects are present and insight into such corrections. for example, interaction can cause a transition to vanish entirely from the optical spectrum.
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arxiv:cond-mat/0510396
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we study the phase stability of the edwards - anderson spin - glass model by analyzing the domain - wall energy. for the bimodal distribution of bonds, a topological analysis of the ground state allows us to separate the system into two regions : the backbone and its environment. we find that the distributions of domain - wall energies are very different in these two regions for the three dimensional ( 3d ) case. although the backbone turns out to have a very high phase stability, the combined effect of these excitations and correlations produces the low global stability displayed by the system as a whole. on the other hand, in two dimensions ( 2d ) we find that the surface of the excitations avoids the backbone. our results confirm that a narrow connection exists between the phase stability of the system and the internal structure of the ground - state. in addition, for both 3d and 2d we are able to obtain the fractal dimension of the domain wall by direct means.
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arxiv:cond-mat/0607565
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in this paper, we study the curvature estimate of the hermitian - yang - mills flow on holomorphic vector bundles. in one simple case, we show that the curvature of the evolved hermitian metric is uniformly bounded away from the analytic subvariety determined by the harder - narasimhan - seshadri filtration of the holomorphic vector bundle.
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arxiv:1611.04272
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the stability of linear dynamic systems with hysteresis in feedback is considered. while the absolute stability for memoryless nonlinearities ( known as lure ' s problem ) can be proved by the well - known circle criterion, the multivalued rate - independent hysteresis poses significant challenges for feedback systems, especially for proof of convergence to an equilibrium state correspondingly set. the dissipative behavior of clockwise input - output hysteresis is considered with two boundary cases of energy losses at reversal cycles. for upper boundary cases of maximal ( parallelogram shape ) hysteresis loop, an equivalent transformation of the closed - loop system is provided. this allows for the application of the circle criterion of absolute stability. invariant sets as a consequence of hysteresis are discussed. several numerical examples are demonstrated, including a feedback - controlled double - mass harmonic oscillator with hysteresis and one stable and one unstable poles configuration.
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arxiv:2002.03423
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non existence of universal not gate for arbitrary quantum mechanical states is a fundamental constraint on the allowed operations performed on physical systems. the largest set of states that can be flipped by using a single not gate is the set of states lying on a great circle of the bloch - sphere. in this paper, we show the impossibility of universal exact - flipping operation, first by using the fact that no faster than light communication is possible and then by using the principle of " non - increase of entanglement under locc ". interestingly, exact flipping of the states of any great circle does not violate these two principles, as expected.
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arxiv:quant-ph/0506154
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organized autotelescopes for serendipitous event survey ( oases ) is an optical observation project that aims to detect and investigate stellar occultation events by kilometer - sized trans - neptunian objects ( tnos ). in this project, multiple low - cost observation systems for wide - field and high - speed photometry were developed in order to detect rare and short - timescale stellar occultation events. the observation system consists of commercial off - the - shelf $ 0. 28 \ { \ rm m } $ aperture $ f / 1. 58 $ optics providing a $ 2. 3 \ times 1. 8 $ square - degree field of view. a commercial cmos camera is coupled to the optics to obtain full - frame imaging with a frame rate greater than $ 10 \ { \ rm hz } $. as of september 2016, this project exploits two observation systems, which are installed on miyako island, okinawa, japan. recent improvements in cmos technology in terms of high - speed imaging and low readout noise mean that the observation systems are capable of monitoring $ \ sim 2000 $ stars in the galactic plane simultaneously with magnitudes down to $ { \ rm v } \ sim 13. 0 $, providing $ \ sim 20 \ % $ photometric precision in light curves with a sampling cadence of $ 15. 4 \ { \ rm hz } $. this number of monitored stars is larger than for any other existing instruments for coordinated occultation surveys. in addition, a precise time synchronization method needed for simultaneous occultation detection is developed using faint meteors. the two oases observation systems are executing coordinated monitoring observations of a dense stellar field in order to detect occultations by kilometer - sized tnos for the first time.
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arxiv:1706.00012
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let $ g = ( v, e ) $ be a connected graph. given a vertex $ v \ in v $ and an edge $ e = uw \ in e $, the distance between $ v $ and $ e $ is defined as $ d _ g ( e, v ) = \ min \ { d _ g ( u, v ), d _ g ( w, v ) \ } $. a nonempty set $ s \ subset v $ is an edge metric generator for $ g $ if for any two edges $ e _ 1, e _ 2 \ in e $ there is a vertex $ w \ in s $ such that $ d _ g ( w, e _ 1 ) \ ne d _ g ( w, e _ 2 ) $. the minimum cardinality of any edge metric generator for a graph $ g $ is the edge metric dimension of $ g $. the edge metric dimension of the join, lexicographic and corona product of graphs is studied in this article.
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arxiv:1809.08900
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the ubiquitous noise in quantum system hinders the advancement of quantum information processing and has driven the emergence of different quantum error correction protocols. among them, quantum error correction codes tailored for noise - biased qubits exhibit comparatively high error thresholds, making them a promising platform to achieve fault - tolerance. nevertheless, their quantum operations are challenging and the demonstration of their performance beyond the fault - tolerant threshold remains incomplete. here, we leverage schr \ " odinger cat states in scalable planar superconducting circuits to thoroughly characterize the high - fidelity single - qubit quantum operations on noise - biased qubits with systematic quantum tomography and benchmarking tools, demonstrating their state - of - the - art performance beyond the fault - tolerant threshold of the surface code. these results thus embody a transformative milestone in the exploration of quantum systems with structured noises. notably, our framework is extensible to other structured - noise systems, paving the way for systematic characterization and validation of novel quantum platforms with structured noise.
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arxiv:2411.04442
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we study the limiting behavior of eigenfunctions / eigenvalues of the laplacian of a family of riemannian metrics that degenerates on a hypersurface. our results generalize earlier work concerning the degeneration of hyperbolic surfaces.
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arxiv:math/0102219
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a vertex set $ u \ subseteq v $ of an undirected graph $ g = ( v, e ) $ is a \ textit { resolving set } for $ g $ if for every two distinct vertices $ u, v \ in v $ there is a vertex $ w \ in u $ such that the distance between $ u $ and $ w $ and the distance between $ v $ and $ w $ are different. a resolving set $ u $ is { \ em fault - tolerant } if for every vertex $ u \ in u $ set $ u \ setminus \ { u \ } $ is still a resolving set. { the \ em ( fault - tolerant ) metric dimension } of $ g $ is the size of a smallest ( fault - tolerant ) resolving set for $ g $. the { \ em weighted ( fault - tolerant ) metric dimension } for a given cost function $ c : v \ longrightarrow \ mathbb { r } _ + $ is the minimum weight of all ( fault - tolerant ) resolving sets. deciding whether a given graph $ g $ has ( fault - tolerant ) metric dimension at most $ k $ for some integer $ k $ is known to be np - complete. the weighted fault - tolerant metric dimension problem has not been studied extensively so far. in this paper we show that the weighted fault - tolerant metric dimension problem can be solved in linear time on cographs.
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arxiv:1904.04243
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we present a very brief description of the hartree - fock method in nuclear structure physics, discuss the numerical methods used to solve the self - consistent equations, and analyze the precision and convergence properties of solutions. as an application we present results pertaining to quadrupole moments and single - particle quadrupole polarizations in superdeformed nuclei with a ~ 60.
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arxiv:nucl-th/9801056
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we consider the observations of an unknown $ s $ - sparse vector $ { \ boldsymbol \ theta } $ corrupted by gaussian noise with zero mean and unknown covariance matrix $ { \ boldsymbol \ sigma } $. we propose minimax optimal methods of estimating the $ \ ell _ 2 $ norm of $ { \ boldsymbol \ theta } $ and testing the hypothesis $ h _ 0 : { \ boldsymbol \ theta } = 0 $ against sparse alternatives when only partial information about $ { \ boldsymbol \ sigma } $ is available, such as an upper bound on its frobenius norm and the values of its diagonal entries to within an unknown scaling factor. we show that the minimax rates of the estimation and testing are leveraged not by the dimension of the problem but by the value of the frobenius norm of $ { \ boldsymbol \ sigma } $.
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arxiv:2407.14778
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in this paper we study a natural decomposition of $ g $ - equivariant $ k $ - theory of a proper $ g $ - space, when $ g $ is a lie group with a compact normal subgroup $ a $ acting trivially. our decomposition could be understood as a generalization of the theory known as mackey machine under suitable hypotheses, since it decomposes $ g $ - equivariant k - theory in terms of twisted equivariant k - theory groups respect to some subgroups of $ g / a $. similar decompositions were known for the case of a compact lie group acting on a space, but our main result applies to discrete, linear and almost connected groups. we also apply this decomposition to study equivariant $ k $ - theory of spaces with only one isotropy type. we provide a rich class of examples in order to expose the strength and generality of our results. we also study the decomposition for equivariant connective $ k $ - homology for actions of compact lie groups using a suitable configuration space model, based on previous papers published by the third author.
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arxiv:2003.09777
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with the recent advent of large interferometric surveys, we can now probe the physical conditions, dynamics, and star - forming properties of molecular gas in the central kpc of starbursts and active galactic nuclei. we present results from the high - resolution ( ~ 100 pc ) interferometric survey of molecular gas in the inner kpc of nearby starbursts ( jogee, kenney, and scoville 2001a ) and the ongoing multi - transition survey of cold, warm, and dense molecular gas in a broad range of active and inactive galactic nuclei ( jogee, baker, sakamoto, and scoville 2001b ).
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arxiv:astro-ph/0201209
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##ly it is the dimension of the image of the linear map represented by a. the rank – nullity theorem states that the dimension of the kernel of a matrix plus the rank equals the number of columns of the matrix. = = square matrix = = a square matrix is a matrix with the same number of rows and columns. an n - by - n matrix is known as a square matrix of order n. any two square matrices of the same order can be added and multiplied. the entries aii form the main diagonal of a square matrix. they lie on the imaginary line running from the top left corner to the bottom right corner of the matrix. = = = main types = = = = = = = diagonal and triangular matrix = = = = if all entries of a below the main diagonal are zero, a is called an upper triangular matrix. similarly, if all entries of a above the main diagonal are zero, a is called a lower triangular matrix. if all entries outside the main diagonal are zero, a is called a diagonal matrix. = = = = identity matrix = = = = the identity matrix in of size n is the n - by - n matrix in which all the elements on the main diagonal are equal to 1 and all other elements are equal to 0, for example, i 1 = [ 1 ], i 2 = [ 1 0 0 1 ], i n = [ 1 0 0 0 1 0 0 0 1 ] { \ displaystyle { \ begin { aligned } \ mathbf { i } _ { 1 } & = { \ begin { bmatrix } 1 \ end { bmatrix } }, \ \ [ 4pt ] \ mathbf { i } _ { 2 } & = { \ begin { bmatrix } 1 & 0 \ \ 0 & 1 \ end { bmatrix } }, \ \ [ 4pt ] \ vdots & \ \ [ 4pt ] \ mathbf { i } _ { n } & = { \ begin { bmatrix } 1 & 0 & \ cdots & 0 \ \ 0 & 1 & \ cdots & 0 \ \ \ vdots & \ vdots & \ ddots & \ vdots \ \ 0 & 0 & \ cdots & 1 \ end { bmatrix } } \ end { aligned } } } it is a square matrix of order n, and also a special kind of diagonal matrix. it is called an identity matrix because multiplication with it
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https://en.wikipedia.org/wiki/Matrix_(mathematics)
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simulations that produce three - dimensional data are ubiquitous in science, ranging from fluid flows to plasma physics. we propose a similarity model based on entropy, which allows for the creation of physically meaningful ground truth distances for the similarity assessment of scalar and vectorial data, produced from transport and motion - based simulations. utilizing two data acquisition methods derived from this model, we create collections of fields from numerical pde solvers and existing simulation data repositories. furthermore, a multiscale cnn architecture that computes a volumetric similarity metric ( volsim ) is proposed. to the best of our knowledge this is the first learning method inherently designed to address the challenges arising for the similarity assessment of high - dimensional simulation data. additionally, the tradeoff between a large batch size and an accurate correlation computation for correlation - based loss functions is investigated, and the metric ' s invariance with respect to rotation and scale operations is analyzed. finally, the robustness and generalization of volsim is evaluated on a large range of test data, as well as a particularly challenging turbulence case study, that is close to potential real - world applications.
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arxiv:2202.04109
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in calculus of variations on general time scales, an integral euler - lagrange equation is usually derived in order to characterize the critical points of non shifted lagrangian functionals, see e. g. [ r. a. c. ferreira and co - authors, optimality conditions for the calculus of variations with higher - order delta derivatives, appl. math. lett., 2011 ]. in this paper, we prove that the nabla - differentiability of the forward jump operator sigma is a sharp assumption in order to obtain an euler - lagrange equation of differential form. furthermore, this differential form allows us to prove a noether - type theorem providing an explicit constant of motion for differential euler - lagrange equations admitting a symmetry.
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arxiv:1302.3623
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common representations of light fields use four - dimensional data structures, where a given pixel is closely related not only to its spatial neighbours within the same view, but also to its angular neighbours, co - located in adjacent views. such structure presents increased redundancy between pixels, when compared with regular single - view images. then, these redundancies are exploited to obtain compressed representations of the light field, using prediction algorithms specifically tailored to estimate pixel values based on both spatial and angular references. this paper proposes new encoding schemes which take advantage of the four - dimensional light field data structures to improve the coding performance of minimum rate predictors. the proposed methods expand previous research on lossless coding beyond the current state - of - the - art. the experimental results, obtained using both traditional datasets and others more challenging, show bit - rate savings no smaller than 10 %, when compared with existing methods for lossless light field compression.
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arxiv:2104.06252
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in this paper we describe our work on enabling fine - grained authorization for resource usage and management. we address the need of virtual organizations to enforce their own polices in addition to those of the resource owners, in regard to both resource consumption and job management. to implement this design, we propose changes and extensions to the globus toolkit ' s version 2 resource management mechanism. we describe the prototype and the policy language that we designed to express fine - grained policies, and we present an analysis of our solution.
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arxiv:cs/0311025
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we examine the physics of the magnetic mirror mode in its final state of saturation, the thermodynamic equilibrium, to demonstrate that the mirror mode is the analogue of a superconducting effect in a classical anisotropic - pressure space plasma. two different spatial scales are identified which control the behaviour of its evolution. these are the ion inertial scale $ \ lambda _ { im } ( \ tau ) $ based on the excess density $ n _ m ( \ tau ) $ generated in the mirror mode, and a correlation length. this can be either the debye length, the ion gyro - radius, or a turbulent correlation length. the mirror mode equilibrium structure under saturation is determined by the landau - ginzburg ratio of these two length scales. mirror modes then behave like type ii superconductors, naturally giving rise to chains of local depletions of the magnetic field of the kind observed in the mirror mode, providing the plasma a short scale magnetic bubble texture. this might be important in the study of magnetic turbulence in plasmas.
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arxiv:1804.10900
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recent llm - based text - to - sql methods usually suffer from significant performance degradation on " huge " databases and complex user questions that require multi - step reasoning. moreover, most existing methods neglect the crucial significance of llms utilizing external tools and model collaboration. to address these challenges, we introduce mac - sql, a novel llm - based multi - agent collaborative framework. our framework comprises a core decomposer agent for text - to - sql generation with few - shot chain - of - thought reasoning, accompanied by two auxiliary agents that utilize external tools or models to acquire smaller sub - databases and refine erroneous sql queries. the decomposer agent collaborates with auxiliary agents, which are activated as needed and can be expanded to accommodate new features or tools for effective text - to - sql parsing. in our framework, we initially leverage gpt - 4 as the strong backbone llm for all agent tasks to determine the upper bound of our framework. we then fine - tune an open - sourced instruction - followed model, sql - llama, by leveraging code llama 7b, to accomplish all tasks as gpt - 4 does. experiments show that sql - llama achieves a comparable execution accuracy of 43. 94, compared to the baseline accuracy of 46. 35 for vanilla gpt - 4. at the time of writing, mac - sql + gpt - 4 achieves an execution accuracy of 59. 59 when evaluated on the bird benchmark, establishing a new state - of - the - art ( sota ) on its holdout test set ( https : / / github. com / wbbeyourself / mac - sql ).
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arxiv:2312.11242
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indirect insights of pop iii stars and black holes ( bhs ) at cosmic dawn ( cd ) may be imprinted as an absorption signal in the 21cm line of hi against the cmb, when the universe was less than 200 myr old. to explain the additional large amplitude of the 21cm hi absorption reported by edges there have been proposed models based on an additional synchrotron cosmic radio background ( crb ) from bh - jet sources that boost the hi absorption signal at cd. the recent observations of radio loud supermassive bhs ( smbhs ) in high - z quasars up to z = 7 suggest the existence of a crb from growing bhs at z > 15, of unknown intensity. to match the onset of the edges signal a crb of comparable intensity to that of the cmb is required. here we provide approximate calculations to analyze this type of absorption signals, taking that of edges as an example. assuming a bh mass to radio luminosity ratio as observed in radio - loud smbhs of ~ 10 ^ 9 solar masses in quasars at z = 6 - 7, we find that rapidly growing radio luminous bhs of intermediate mass ( imbhs ) in their way to become smbhs, are the only type of astrophysical radio sources of a crb that could explain the amplitude of the hi absorption reported by edges in the interval of z = 18 - 20. at those redshifts the edges signal would imply that the global mass density of imbhs must be dominant over that of stars, more than 70 % of the maximum stellar mass density ( smd ) expected at those high redshifts. this suggests that those imbhs are formed before and grow faster than the bulk of stars, with no large mass contribution from stellar - mass bh remnants of typical pop iii stars. the highly redshifted signals from these imbhs may be detected at long radio wavelengths with ultrasensitive interferometers such as the ska, in the infrared with the jwst, and in the x - rays with future space missions.
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arxiv:2203.12741
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we present a detailed study of quantum oscillations in the antiferromagnetically ordered pnictide compound srfe $ _ 2 $ as $ _ 2 $ as the angle between the applied magnetic field and crystalline axes is varied. our measurements were performed on high quality single crystals in a superconducting magnet, and in pulsed magnetic fields up to 60 t, allowing us to observe orbits from several small fermi surface pockets. we extract the cyclotron effective mass $ m ^ { \ star } $ and frequency $ f $ for these orbits and track their values as the field is rotated away from the c - axis. while a constant ratio of $ m ^ { \ star } / f $ is observed for one orbit as expected for a parabolic band, a clear deviation is observed for another. we conclude that this deviation points to an orbit derived from a band with dirac dispersion near the fermi level.
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arxiv:1107.1704
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the activity - based workspace ( abw ) paradigm is becoming more popular in commercial office spaces. in this strategy, occupants are given a choice of spaces to do their work and personal activities on a day - to - day basis. this paper shows the implementation and testing of the spacematch platform that was designed to improve the allocation and management of abw. an experiment was implemented to test the ability to characterize the preferences of occupants to match them with suitable environmentally - comfortable and spatially - efficient flexible workspaces. this approach connects occupants with a catalog of available work desks using a web - based mobile application and enables them to provide real - time environmental feedback. in this work, we tested the ability for this feedback data to be merged with indoor environmental values from internet - of - things ( iot ) sensors to optimize space and energy use by grouping occupants with similar preferences. this paper outlines a case study implementation of this platform on two office buildings. this deployment collected 1, 182 responses from 25 field - based research participants over a 30 - day study. from this initial data set, the results show that the abw occupants can be segmented into specific types of users based on their accumulated preference data, and matching preferences can be derived to build a recommendation platform.
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arxiv:2006.09570
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twenty - one centimeter tomography is emerging as a powerful tool to explore the end of the cosmic dark ages and the reionization epoch, but it will only be as good as our ability to accurately model and remove astrophysical foreground contamination. previous treatments of this problem have focused on the angular structure of the signal and foregrounds and what can be achieved with limited spectral resolution ( bandwidths in the 1 mhz range ). in this paper we introduce and evaluate a ` ` blind ' ' method to extract the multifrequency 21cm signal by taking advantage of the smooth frequency structure of the galactic and extragalactic foregrounds. we find that 21 cm tomography is typically limited by foregrounds on scales $ k \ ll 1h / $ mpc and limited by noise on scales $ k \ gg 1h / $ mpc, provided that the experimental bandwidth can be made substantially smaller than 0. 1 mhz. our results show that this approach is quite promising even for scenarios with rather extreme contamination from point sources and diffuse galactic emission, which bodes well for upcoming experiments such as lofar, mwa, past, and ska.
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arxiv:astro-ph/0501081
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a phenomenological turbulence model for kinetic alfv \ ' en waves in a magnetizedcollisionless plasma, able to reproduce the non - universalpower - law spectra observed at the sub - ion scales in the solar wind and the terrestrial magnetosphere, is presented. the process of temperature homogenization along distortedmagnetic field lines, induced by landau damping, affects the turbulencetransfer time and results in a steepening of the sub - ion power - law spectrumof critically - balanced turbulence, whose exponent is sensitive to the ratio between the alfv \ ' en wave period and the nonlinear timescale. transition from large - scaleweak turbulence to smaller scale strong turbulence is capturedand non local interactions, relevant in the case of steep spectra, are accounted for.
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arxiv:1509.02839
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national and international guidelines for trustworthy artificial intelligence ( ai ) consider explainability to be a central facet of trustworthy systems. this paper outlines a multi - disciplinary rationale for explainability auditing. specifically, we propose that explainability auditing can ensure the quality of explainability of systems in applied contexts and can be the basis for certification as a means to communicate whether systems meet certain explainability standards and requirements. moreover, we emphasize that explainability auditing needs to take a multi - disciplinary perspective, and we provide an overview of four perspectives ( technical, psychological, ethical, legal ) and their respective benefits with respect to explainability auditing.
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arxiv:2108.07711
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the rapid advancement of the automotive industry towards automated and semi - automated vehicles has rendered traditional methods of vehicle interaction, such as touch - based and voice command systems, inadequate for a widening range of non - driving related tasks, such as referencing objects outside of the vehicle. consequently, research has shifted toward gestural input ( e. g., hand, gaze, and head pose gestures ) as a more suitable mode of interaction during driving. however, due to the dynamic nature of driving and individual variation, there are significant differences in drivers ' gestural input performance. while, in theory, this inherent variability could be moderated by substantial data - driven machine learning models, prevalent methodologies lean towards constrained, single - instance trained models for object referencing. these models show a limited capacity to continuously adapt to the divergent behaviors of individual drivers and the variety of driving scenarios. to address this, we propose \ textit { icregress }, a novel regression - based incremental learning approach that adapts to changing behavior and the unique characteristics of drivers engaged in the dual task of driving and referencing objects. we suggest a more personalized and adaptable solution for multimodal gestural interfaces, employing continuous lifelong learning to enhance driver experience, safety, and convenience. our approach was evaluated using an outside - the - vehicle object referencing use case, highlighting the superiority of the incremental learning models adapted over a single trained model across various driver traits such as handedness, driving experience, and numerous driving conditions. finally, to facilitate reproducibility, ease deployment, and promote further research, we offer our approach as an open - source framework at \ url { https : / / github. com / amrgomaaelhady / icregress }.
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arxiv:2401.16123
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maximum tsallis entropy ( mte ) framework in reinforcement learning has gained popularity recently by virtue of its flexible modeling choices including the widely used shannon entropy and sparse entropy. however, non - shannon entropies suffer from approximation error and subsequent underperformance either due to its sensitivity or the lack of closed - form policy expression. to improve the tradeoff between flexibility and empirical performance, we propose to strengthen their error - robustness by enforcing implicit kullback - leibler ( kl ) regularization in mte motivated by munchausen dqn ( mdqn ). we do so by drawing connection between mdqn and advantage learning, by which mdqn is shown to fail on generalizing to the mte framework. the proposed method tsallis advantage learning ( tal ) is verified on extensive experiments to not only significantly improve upon tsallis - dqn for various non - closed - form tsallis entropies, but also exhibits comparable performance to state - of - the - art maximum shannon entropy algorithms.
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arxiv:2205.07885
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recent results on the entirely analytic calculation of second order corrections to massive quark pair production vertices induced by light quark flavours are reviewed. based on the method presented in this talk the second order effects of the insertion of any massless one - loop vacuum polarization into the gluon line of the first order diagrams can be determined. the behaviour of the corrections at threshold for vector and axial - vector current induced massive quark production is discussed.
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arxiv:hep-ph/9606288
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traditional evaluation metrics like rouge compare lexical overlap between the reference and generated summaries without taking argumentative structure into account, which is important for legal summaries. in this paper, we propose a novel legal summarization evaluation framework that utilizes gpt - 4 to generate a set of question - answer pairs that cover main points and information in the reference summary. gpt - 4 is then used to generate answers based on the generated summary for the questions from the reference summary. finally, gpt - 4 grades the answers from the reference summary and the generated summary. we examined the correlation between gpt - 4 grading with human grading. the results suggest that this question - answering approach with gpt - 4 can be a useful tool for gauging the quality of the summary.
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arxiv:2309.15016
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to improve light yield and energy resolution in large - volume neutrino detectors, light concentrators are often mounted on photomultiplier tubes to increase the detection efficiency of optical photons from scintillation or cherenkov light induced by charged particles. we propose a method to optimize previous light concentrators design in order to attain a field of view of 90 degrees and a geometrical collection efficiency above 98 %. this improvement could be crucial to jinping and other future neutrino experiments whichever it is applicable.
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arxiv:1703.07527
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the steady - state of a generalized coagulation - decoagulation model on a one - dimensional lattice with reflecting boundaries is studied using a matrix - product approach. it is shown that the quadratic algebra of the model has a four - dimensional representation provided that some constraints on the microscopic reaction rates are fulfilled. the dynamics of a product shock measure with two shock fronts, generated by the hamiltonian of this model, is also studied. it turns out that the shock fronts move on the lattice as two simple random walkers which repel each other provided that the same constraints on the microscopic reaction rates are satisfied.
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arxiv:0804.2524
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i present the latest results from a search for hot molecular cores at mid - infrared wavelengths from the largest optical telescopes available at the present time. three well - observed hot molecular cores were imaged, g29. 96 - 0. 02, g19. 61 - 0. 23, and g34. 26 + 0. 15. even though mid - infrared sources have been claimed to be detected previously at the hot molecular core locations of both g19. 61 - 0. 23 and g34. 26 + 0. 15, only the hot molecular core in g29. 96 - 0. 02 resulted in a detection. new upper limits on mid - infrared emission are given for the hot molecular cores that were not detected.
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arxiv:astro-ph/0207336
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we establish optimal lebesgue estimates for a class of generalized radon transforms defined by averaging functions along polynomial - like curves. the presence of an essentially optimal weight allows us to prove uniform estimates, wherein the lebesgue exponents are completely independent of the curves and the operator norms depend only on the polynomial degree. moreover, our weighted estimates possess rather strong diffeomorphism invariance properties, allowing us to obtain uniform bounds for averages on curves satisfying a natural nilpotency hypothesis.
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arxiv:1710.07688
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given a classical $ r $ - matrix on a poisson algebra, we show how to construct a natural family of compatible poisson structures for the hamiltonian formulation of lax equations. examples for which our formalism applies include the benny hierachy, the dispersionless toda lattice hierachy, the dispersionless kp and modified kp hierachies, the dispersionless dym hierachy etc.
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arxiv:math-ph/0506029
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recent work has demonstrated that deep neural networks are vulnerable to adversarial examples - - - inputs that are almost indistinguishable from natural data and yet classified incorrectly by the network. in fact, some of the latest findings suggest that the existence of adversarial attacks may be an inherent weakness of deep learning models. to address this problem, we study the adversarial robustness of neural networks through the lens of robust optimization. this approach provides us with a broad and unifying view on much of the prior work on this topic. its principled nature also enables us to identify methods for both training and attacking neural networks that are reliable and, in a certain sense, universal. in particular, they specify a concrete security guarantee that would protect against any adversary. these methods let us train networks with significantly improved resistance to a wide range of adversarial attacks. they also suggest the notion of security against a first - order adversary as a natural and broad security guarantee. we believe that robustness against such well - defined classes of adversaries is an important stepping stone towards fully resistant deep learning models. code and pre - trained models are available at https : / / github. com / madrylab / mnist _ challenge and https : / / github. com / madrylab / cifar10 _ challenge.
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arxiv:1706.06083
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hybrid higgs inflation model is a hybrid type of the so - called higgs inflation model with the conventional non - minimal $ \ xi $ coupling to a scalar curvature $ r $ and new higgs inflation model with the derivative coupling to the einstein curvature tensor $ g _ { \ mu \ nu } $. this model can explain all possible value of the tensor - to - scalar ratio $ r $ allowed by the present cmb constraints with an appropriate choice of coupling parameters. however the derivative coupling may causes a gradient instability during oscillation phase after inflation just as in new higgs inflation model. analyzing the behaviours of perturbations during oscillation phase in the hybrid higgs inflation model, we show that the unstable scalar modes found in new higgs inflation model are stabilized by the non - minimal $ \ xi $ coupling for some range of the coupling parameters.
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arxiv:2001.00154
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we present 1. 3 and 3. 2 mm continuum maps of three star forming regions in the large magellanic cloud ( lmc ) observed with the atacama large millimeter / submillimeter array ( alma ). the data were taken as part of two projects retrieved from the alma public archive plus one project observed specifically for this work. we develop a technique to combine maps at these wavelengths to estimate dust - only emission corrected for free - free emission contamination. from these observations we identify 32 molecular clumps in the lmc and estimate their total mass from their dust emission to range from 205 to 5740 m $ _ { \ odot } $. we derive a cumulative clump mass function ( $ n ( \ geq m ) \ propto m ^ { \ alpha + 1 } $ ) and fit it with a double power law to find $ \ alpha _ { \ mathrm { low } } = - 1. 76 ^ { + 0. 04 } _ { - 0. 05 } $, $ \ alpha _ { \ mathrm { high } } = - 3. 3 \ pm 0. 2 $, and a break mass of 2500 $ ^ { + 300 } _ { - 200 } $ m $ _ { \ odot } $. a comparison to the 30 doradus - 10 mass function derived previously from co ( 2 - 1 ) data reveals a consistent range of clump masses and good agreement between the fitted slopes. we also find that the low mass index of the lmc mass function agrees well with the high mass index for core and clump mass functions from several star forming regions in the milky way. this agreement may indicate an extension of the milky way power law to higher masses than previously observed.
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arxiv:1811.07994
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we investigate crack propagation in a simple two - dimensional visco - elastic model and find a scaling regime in the relation between the propagation velocity and energy release rate or fracture energy, together with lower and upper bounds of the scaling regime. on the basis of our result, the existence of the lower and upper bounds is expected to be universal or model - independent : the present simple simulation model provides generic insight into the physics of crack propagation, and the model will be a first step towards the development of a more refined coarse - grained model. relatively abrupt changes of velocity are predicted near the lower and upper bounds for the scaling regime and the positions of the bounds could be good markers for the development of tough polymers, for which we provide simple views that could be useful as guiding principles for toughening polymer - based materials.
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arxiv:1705.05076
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we investigate the gravitational effect on landau levels. we show that the familiar infinite landau degeneracy of the energy levels of a quantum particle moving inside a uniform and constant magnetic field is removed by the interaction of the particle with a gravitational field. two independent approaches are used to solve the relevant schr \ " odinger equation within the newtonian approximation. it is found that both approaches yield qualitatively similar results within their respective approximations. with the goal of clarifying some results found in the literature concerning the use of a third independent approach for extracting the quantization condition based on a similar differential equation, we show that such an approach cannot yield a general and yet consistent result. we point out to the more accurate, but impractical, way to use such an approach ; a way which does in principle yield a consistent quantization condition. we discuss how our results could be used to contribute in a novel way to the existing methods for testing gravity at the tabletop experiments level as well as at the astrophysical observational level by deriving the corrections brought by yukawa - like and power - law deviations from the inverse - square law. the full relativistic regime is also examined in detail.
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arxiv:1909.01827
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as the title suggests, this is the third paper in a series addressing bilevel optimization problems that are governed by the kantorovich problem of optimal transport. these tasks can be reformulated as mathematical problems with complementarity constraints in the space of regular borel measures. due to the nonsmoothness that is introduced by the complementarity constraints, such problems are often regularized, for instance, using entropic regularization. in this series of papers, however, we apply a quadratic regularization to the kantorovich problem. by doing so, we enhance its numerical properties while preserving the sparsity structure of the optimal transportation plan as much as possible. while the first two papers in this series focus on the well - posedness of the regularized bilevel problems and the approximation of solutions to the bilevel optimization problem in the infinite - dimensional case, in this paper, we reproduce these results for the finite - dimensional case and present findings that go well beyond the ones of the previous papers and pave the way for the numerical treatment of the bilevel problems.
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arxiv:2406.08992
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formal software verification techniques are widely used to specify and prove the functional correctness of programs. however, nonfunctional properties such as time complexity are usually carried out with pen and paper. inefficient code in terms of time complexity may cause massive performance problems in large - scale complex systems. we present a proof of concept for using the dafny verification tool to specify and verify the worst - case time complexity of binary search. this approach can also be used for academic purposes as a new way to teach algorithms and complexity.
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arxiv:2108.02966
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we define and study the plancherel - hecke probability measure on young diagrams ; the hecke algorithm of [ buch - kresch - shimozono - tamvakis - yong ' 06 ] is interpreted as a polynomial - time exact sampling algorithm for this measure. using the results of [ thomas - yong ' 07 ] on jeu de taquin for increasing tableaux, a symmetry property of the hecke algorithm is proved, in terms of longest strictly increasing / decreasing subsequences of words. this parallels classical theorems of [ schensted ' 61 ] and of [ knuth ' 70 ], respectively, on the schensted and robinson - schensted - knuth algorithms. we investigate, and conjecture about, the limit typical shape of the measure, in analogy with work of [ vershik - kerov ' 77 ], [ logan - shepp ' 77 ] and others on the ` ` longest increasing subsequence problem ' ' for permutations. we also include a related extension of [ aldous - diaconis ' 99 ] on patience sorting. together, these results provide a new rationale for the study of increasing tableau combinatorics, distinct from the original algebraic - geometric ones concerning k - theoretic schubert calculus.
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arxiv:0801.1319
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we report simulations of a two - dimensional, dense, bidisperse system of inelastic hard disks falling down a vertical tube under the influence of gravity. we examine the approach to jamming as the average flow of particles down the tube is slowed by making the outlet narrower. defining coarse - grained velocity and stress fields, we study two - point temporal and spatial correlation functions of these fields in a region of the tube where the time - averaged velocity is spatially uniform. we find that fluctuations in both velocity and stress become increasingly correlated as the system approaches jamming. we extract a growing length scale and time scale from these correlations.
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arxiv:0806.2413
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pricing of high - dimensional options is one of the most important problems in mathematical finance. the objective of this manuscript is to present an original self - contained treatment of the multidimensional pricing. during the past decades the black - scholes this model, which essentially is based on the log - normal assumption, has been increasingly criticised. in particular, it was noticed by mandelbrot that empirical log - returns distributions are more concentrated around the origin and have considerably heavier tails. this suggests to adjust the black - scholes model by the introduction of the levy processes instead of brownian ones. this approach has been extensively studied in a univariate setup since the nineties. in the multivariate settings the theory is not so advanced. we present a general method of high - dimensional option pricing based on a wide range of jump - diffusion models. namely, we construct approximation formulas for the price of spread options. it is important to get an efficient approximation for the respective density function, since the reward function has usually a simple structure. instead of a commonly used tabulation approach, we use the respective m - widths to compare a wide range of numerical methods. we give an algorithm of almost optimal, in the sense of the respective m - widths, reconstruction of density functions. to demonstrate the power of our approach we consider in details a concrete class of levy driven processes and present the respective rates of convergence of approximation formulas. the interrelationship between the theory and tools reflects the richness and deep connections in financial mathematics, stochastic processes, theory of martingales, functional analysis, topology and harmonic analysis.
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arxiv:1510.07221
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in this paper i show that it is possible to use regge theory to constrain the initial parton distribution functions of a global dglap fit. in this approach, both quarks and gluons have the same high - energy behaviour which may also be used to describe soft interactions. more precisely, i show that, if we parametrise the parton distributions with a triple - pole pomeron, { \ em i. e. } like $ \ log ^ 2 ( 1 / x ) $ at small $ x $, at $ q ^ 2 = q _ 0 ^ 2 $ and evolve these distribution with the dglap equation, we can reproduce $ f _ 2 ^ p $, $ f _ 2 ^ d $, $ f _ 2 ^ n / f _ 2 ^ p $, $ f _ 2 ^ { \ nu n } $ and $ xf _ 3 ^ { \ nu n } $ for $ w ^ 2 \ ge 12. 5 $ gev $ ^ 2 $. in this case, we obtain a new leading - order global qcd fit with a regge - compatible initial condition. i shall also show that it is possible to use regge theory to extend the parton distribution functions to small $ q ^ 2 $. this leads to a description of the structure functions over the whole $ q ^ 2 $ range based on regge theory at low $ q ^ 2 $ and on qcd at large $ q ^ 2 $. finally, i shall argue that, at large $ q ^ 2 $, the parton distribution functions obtained from dglap evolution and containing an essential singularity at $ j = 1 $ can be approximated by a triple - pole pomeron behaviour.
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arxiv:hep-ph/0407098
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using transport theory to model central au + au collisions in the energy region of 20 - 110 mev / u, at impact parameters b < = 5 fm, we predict a measurable impact of spinoidal instability as the collective expansion sets in with energy. two transport models are employed, the pbuu model, solving a boltzmann - uehling - uhlenbeck equation, and the brownian motion ( bm ) model, solving a set of langevin equations to describe the motion of individual nucleons in a noisy nuclear medium. we find without ambiguity, for the first time, that a combination of delayed equilibration, onset of collective expansion and the spinodal instability produces a pair of transient ring structures, made of the projectile and target remnants, with spectator nucleons predicted to end in the entities reminiscent of stones in jewelry, on the rings. the ring structures, calculated in the configuration space and mapped onto the velocity space, could be detected in experimental collective flow data.
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arxiv:1910.10500
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measurement procedures of most rise - and - fall absolute gravimeters has to resolve singularity at the apex of the trajectory caused by the discrete fringe counting in the michelson - type interferometers. traditionally the singularity is addressed by implementing non - linear models of the trajectory, but they introduce problems of their own, such as biasness, non - uniqueness, and instability of the gravity estimates. using imgc - 02 gravimeter as example, we show that the measurement procedure of the rise - and - fall gravimeters can be based on the linear models which successfully resolve the singularity and provide rigorous estimates of the gravity value. the linear models also facilitate further enhancements of the instrument, such as accounting for new types of disturbances and active compensation for the vibrations.
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arxiv:1312.7291
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detecting non - termination is crucial for ensuring program correctness and security, such as preventing denial - of - service attacks. while termination analysis has been studied for many years, existing methods have limited scalability and are only effective on small programs. to address this issue, we propose a practical termination checking technique, called endwatch, for detecting non - termination caused by infinite loops through testing. specifically, we introduce two methods to generate non - termination oracles based on checking state revisits, i. e., if the program returns to a previously visited state at the same program location, it does not terminate. the non - termination oracles can be incorporated into testing tools ( e. g., afl used in this paper ) to detect non - termination in large programs. for linear loops, we perform symbolic execution on individual loops to infer state revisit conditions ( srcs ) and instrument srcs into target loops. for non - linear loops, we instrument target loops for checking concrete state revisits during execution. we evaluated endwatch on standard benchmarks with small - sized programs and real - world projects with large - sized programs. the evaluation results show that endwatch is more effective than the state - of - the - art tools on standard benchmarks ( detecting 87 % of non - terminating programs while the best baseline detects only 67 % ), and useful in detecting non - termination in real - world projects ( detecting 90 % of known non - termination cves and 4 unknown bugs ).
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arxiv:2312.03335
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left r - module, soc ( rr ) is defined. both of these socles are ring ideals, and it is known they are not necessarily equal. if m is an artinian module, soc ( m ) is itself an essential submodule of m. in fact, if m is a semiartinian module, then soc ( m ) is itself an essential submodule of m. additionally, if m is a non - zero module over a left semi - artinian ring, then soc ( m ) is itself an essential submodule of m. this is because any non - zero module over a left semi - artinian ring is a semiartinian module. a module is semisimple if and only if soc ( m ) = m. rings for which soc ( m ) = m for all m are precisely semisimple rings. soc ( soc ( m ) ) = soc ( m ). m is a finitely cogenerated module if and only if soc ( m ) is finitely generated and soc ( m ) is an essential submodule of m. since the sum of semisimple modules is semisimple, the socle of a module could also be defined as the unique maximal semisimple submodule. from the definition of rad ( r ), it is easy to see that rad ( r ) annihilates soc ( r ). if r is a finite - dimensional unital algebra and m a finitely generated r - module then the socle consists precisely of the elements annihilated by the jacobson radical of r. = = socle of a lie algebra = = in the context of lie algebras, a socle of a symmetric lie algebra is the eigenspace of its structural automorphism that corresponds to the eigenvalue −1. ( a symmetric lie algebra decomposes into the direct sum of its socle and cosocle. ) = = see also = = injective hull radical of a module cosocle = = references = = alperin, j. l. ; bell, rowen b. ( 1995 ). groups and representations. springer - verlag. p. 136. isbn 0 - 387 - 94526 - 1. anderson, frank wylie ; fuller, kent r. ( 1992 ). rings and categories of modules. springer - verlag. isbn 978 - 0 - 387 - 97845 - 1. robinson, derek j. s. ( 1996 ),
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https://en.wikipedia.org/wiki/Socle_(mathematics)
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we study optical conductivities for high - tc superconductors under the magnetic field on the basis of the microscopic fermi liquid theory. current vertex corrections ( cvc ' s ) are correctly taken into account to satisfy the conservation laws, which has been performed for the first time for optical conductivities based on the fluctuation - exchange ( flex ) approximation. we find that the cvc emphasizes the $ \ omega $ - dependence of $ \ sigma _ { xy } ( \ omega ) $ significantly when the antiferromagnetic ( af ) fluctuations are strong. by this reason, the relation $ \ sigma _ { xy } ( \ omega ) \ sim { \ sigma ( \ omega ) } ^ 2 $, which is satisfied in the extended - drude model given by the relaxation time approximation ( rta ), is totally violated for a wide range of frequencies. consequently, the optical hall coefficient $ r _ h ( \ omega ) $ strongly depends on $ \ omega $ below the infrared frequencies, which is consistent with experimental observations. we also study the mystery about a simple - drude form of the optical hall angle $ \ theta _ h ( \ omega ) $ observed by drew et al., which is highly nontrivial in terms of the rta since the strong $ \ omega $ - dependence of the relaxation time should modify the drude - form. we find that a simple drude - form of $ \ theta _ h ( \ omega ) $ is realized because the $ \ omega $ - dependence of the cvc almost cancels that of the relaxation time. in conclusion, anomalous optical transport phenomena in high - tc superconductors, which had been frequently assumed as an evidence of the breakdown of the fermi liquid state, are well understood in terms of the nearly af fermi liquid once the cvc is taken into account.
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arxiv:cond-mat/0511015
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we consider the classification, up to unitary equivalence, of commuting n - tuples of isometries. we pay special attention to the case when the product of the isometries is a shift of finite multiplicity, and we provide a complete classification when this multiplicity equals n. when n = 2, we identify a pivotal operator which captures many of the properties of a bi - isometry.
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arxiv:math/0606257
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in many applications, training machine learning models involves using large amounts of human - annotated data. obtaining precise labels for the data is expensive. instead, training with weak supervision provides a low - cost alternative. we propose a novel weak supervision algorithm that processes noisy labels, i. e., weak signals, while also considering features of the training data to produce accurate labels for training. our method searches over classifiers of the data representation to find plausible labelings. we call this paradigm data consistent weak supervision. a key facet of our framework is that we are able to estimate labels for data examples low or no coverage from the weak supervision. in addition, we make no assumptions about the joint distribution of the weak signals and true labels of the data. instead, we use weak signals and the data features to solve a constrained optimization that enforces data consistency among the labels we generate. empirical evaluation of our method on different datasets shows that it significantly outperforms state - of - the - art weak supervision methods on both text and image classification tasks.
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arxiv:2202.03987
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, and that " if the us is going to be competitive on the global stage with evs, through 2030 they ’ re going to have to use chinese batteries ". = = security concerns = = in december 2023, duke energy disconnected catl batteries from marine corps base camp lejeune due to security concerns. catl called accusations about its batteries posing espionage threats " false and misleading. " the national defense authorization act for fiscal year 2024 prohibited us defense funding for catl products. in june 2024, a group of u. s. lawmakers asked the united states department of homeland security to add catl to an import ban list under the uyghur forced labor prevention act. catl said in a statement that the allegations against it were " groundless and completely false " and that it was in compliance with applicable laws and regulations. in april 2025, the united states house select committee on strategic competition between the united states and the chinese communist party asked jpmorgan chase and bank of america to withdraw from working on catl ' s hong kong ipo. = = see also = = list of electric - vehicle - battery manufacturers = = references = = = = external links = = official website
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https://en.wikipedia.org/wiki/CATL
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we augment the ` quasi - symmetric stellarator repository ' ( quasr ) to include vacuum field stellarators with quasihelical symmetry using a globalized optimization workflow. the database now has almost 370, 000 quasisaxisymmetry and quasihelically symmetric devices along with coil sets, optimized for a variety of aspect ratios, rotational transforms, and discrete rotational symmetries. this paper outlines a couple of ways to explore and characterize the data set. we plot devices on a near - axis quasisymmetry landscape, revealing close correspondence to this predicted landscape. we also use principal component analysis to reduce the dimensionality of the data so that it can easily be visualized in two or three dimensions. principal component analysis also gives a mechanism to compare the new devices here to previously published ones in the literature. we are able to characterize the structure of the data, observe clusters, and visualize the progression of devices in these clusters. the topology of the data is governed by the interplay of the design constraints and valleys of the quasisymmetry objective. these techniques reveal that the data has structure, and that typically one, two or three principal components are sufficient to characterize it. the latest version of quasr is archived at https : / / zenodo. org / doi / 10. 5281 / zenodo. 10050655 and can be explored online at quasr. flatironinstitute. org.
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arxiv:2409.04826
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we calculate bisoliton solutions using a slowly varying stroboscopic equation. the system is characterized in terms of a single dimensionless parameter. we find two branches of solutions and describe the structure of the tails for the lower branch solutions.
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arxiv:physics/0609246
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we introduce a new theorem prover for classical higher - order logic named auto2. the prover is designed to make use of human - specified heuristics when searching for proofs. the core algorithm is a best - first search through the space of propositions derivable from the initial assumptions, where new propositions are added by user - defined functions called proof steps. we implemented the prover in isabelle / hol, and applied it to several formalization projects in mathematics and computer science, demonstrating the high level of automation it can provide in a variety of possible proof tasks.
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arxiv:1605.07577
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in this paper we present a unifying geometric and compositional framework for modeling complex physical network dynamics as port - hamiltonian systems on open graphs. basic idea is to associate with the incidence matrix of the graph a dirac structure relating the flow and effort variables associated to the edges, internal vertices, as well as boundary vertices of the graph, and to formulate energy - storing or energy - dissipating relations between the flow and effort variables of the edges and internal vertices. this allows for state variables associated to the edges, and formalizes the interconnection of networks. examples from different origins such as consensus algorithms are shown to share the same structure. it is shown how the identified hamiltonian structure offers systematic tools for the analysis of the resulting dynamics.
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arxiv:1107.2006
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interference between fully - independent faint laser sources over two 8. 5 - km full polarization - controlled fiber links was performed, with stable visibility of 47. 8 %, an essential step towards practical implementation of quantum communication protocols.
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arxiv:1208.0866
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world models significantly enhance hierarchical understanding, improving data integration and learning efficiency. to explore the potential of the world model in the remote sensing ( rs ) field, this paper proposes a label - efficient remote sensing world model for multimodal data fusion ( fusdreamer ). the fusdreamer uses the world model as a unified representation container to abstract common and high - level knowledge, promoting interactions across different types of data, \ emph { i. e. }, hyperspectral ( hsi ), light detection and ranging ( lidar ), and text data. initially, a new latent diffusion fusion and multimodal generation paradigm ( lamg ) is utilized for its exceptional information integration and detail retention capabilities. subsequently, an open - world knowledge - guided consistency projection ( ok - cp ) module incorporates prompt representations for visually described objects and aligns language - visual features through contrastive learning. in this way, the domain gap can be bridged by fine - tuning the pre - trained world models with limited samples. finally, an end - to - end multitask combinatorial optimization ( muco ) strategy can capture slight feature bias and constrain the diffusion process in a collaboratively learnable direction. experiments conducted on four typical datasets indicate the effectiveness and advantages of the proposed fusdreamer. the corresponding code will be released at https : / / github. com / cimy - wang / fusdreamer.
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arxiv:2503.13814
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closure space has proven to be a useful tool to restructure lattices and various order structures. this paper aims to provide a novel approach to characterizing some important kinds of continuous domains by means of closure spaces. by introducing an additional map into a given closure space, the notion of f - augmented generalized closure space is presented. it is shown that f - augmented generalized closure spaces generate exactly continuous domains. moreover, the notion of approximable mapping is identified to represent scott - continuous functions between continuous domains. these results produce a category equivalent to that of continuous domains with scottcontinuous functions. at the same time, two subclasses of f - augmented generalized closure spaces are considered which are representations of continuous l - domains and continuous bounded complete domains, respectively.
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arxiv:1809.05049
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we study the stability and electronic structure of previously unexplored two - dimensional ( 2d ) ternary compounds bnp $ _ 2 $ and c $ _ 2 $ sis. using $ ab $ $ initio $ density functional theory, we have identified four stable allotropes of each ternary compound and confirmed their stability by calculated phonon spectra and molecular dynamics simulations. whereas all bnp $ _ 2 $ allotropes are semiconducting, we find c $ _ 2 $ sis, depending on the allotrope, to be semiconducting or semimetallic. the fundamental band gaps of the semiconducting allotropes we study range from $ 1. 4 $ ev to $ 2. 2 $ ev at the hse06 level $ 0. 5 $ ev to $ 1. 4 $ ev at the pbe level and display carrier mobilities as high as $ 1. 5 { \ times } 10 ^ 5 $ cm $ ^ 2 $ v $ ^ { - 1 } $ s $ ^ { - 1 } $. such high mobilities are quite uncommon in semiconductors with so wide band gaps. structural ridges in the geometry of all allotropes cause a high anisotropy in their mechanical and transport properties, promising a wide range of applications in electronics and optoelectronics.
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arxiv:2011.04951
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the problem of reconstructing and identifying intracellular protein signaling and biochemical networks is of critical importance in biology today. we sought to develop a mathematical approach to this problem using, as a test case, one of the most well - studied and clinically important signaling networks in biology today, the epidermal growth factor receptor ( egfr ) driven signaling cascade. more specifically, we suggest a method, augmented sparse reconstruction, for the identification of links among nodes of ordinary differential equation ( ode ) networks from a small set of trajectories with different initial conditions. our method builds a system of representation by using a collection of integrals of all given trajectories and by attenuating block of terms in the representation itself. the system of representation is then augmented with random vectors, and minimization of the 1 - norm is used to find sparse representations for the dynamical interactions of each node. augmentation by random vectors is crucial, since sparsity alone is not able to handle the large error - in - variables in the representation. augmented sparse reconstruction allows to consider potentially very large spaces of models and it is able to detect with high accuracy the few relevant links among nodes, even when moderate noise is added to the measured trajectories. after showing the performance of our method on a model of the egfr protein network, we sketch briefly the potential future therapeutic applications of this approach.
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arxiv:0705.3989
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we study surface states of topological crystalline insulators and superconductors protected by inversion symmetry. these fall into the category of " higher - order " topological insulators and superconductors which possess surface states that propagate along one - dimensional curves ( hinges ) or are localized at some points ( corners ) on the surface. we show that the surface states of higher - order topological insulators and superconductors can be thought of as globally irremovable topological defects and provide a complete classification of these inversion - protected phases in any spatial dimension for the ten symmetry classes by means of a layer construction. furthermore, we discuss possible physical realizations of such states starting with a time - reversal invariant topological insulator ( class aii ) in three dimensions or a time - reversal invariant topological superconductor ( class diii ) in two or three dimensions. the former can be used to build a three - dimensional second - order topological insulator which exhibits one - dimensional chiral or helical modes propagating along opposite edges, whereas the latter enables the construction of three - dimensional third - order or two - dimensional second - order topological superconductors hosting majorana zero modes localized to two opposite corners. being protected by inversion, such states are not pinned to a specific pair of edges or corners thus offering the possibility of controlling their location by applying inversion - symmetric perturbations such as magnetic field.
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arxiv:1801.10050
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the need to smoothly cover a computational domain of interest generically requires the adoption of several grids. to solve the problem of interest under this grid - structure one must ensure the suitable transfer of information among the different grids involved. in this work we discuss a technique that allows one to construct finite difference schemes of arbitrary high order which are guaranteed to satisfy linear numerical and strict stability. the technique relies on the use of difference operators satisfying summation by parts and { \ it penalty techniques } to transfer information between the grids. this allows the derivation of semidiscrete energy estimates for problems admitting such estimates at the continuum. we analyze several aspects of this technique when used in conjuction with high order schemes and illustrate its use in one, two and three dimensional numerical relativity model problems with non - trivial topologies, including truly spherical black hole excision.
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arxiv:gr-qc/0507004
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we introduce eccoplanets, an open - source python code that simulates condensation in the protoplanetary disk. our aim is to analyse how well a simplistic model can reproduce the main characteristics of rocky planet formation. for this purpose, we revisited condensation temperatures ( $ t _ c $ ) as a means to study disk chemistry, and explored their sensitivity to variations in pressure ( p ) and elemental abundance pattern. we also examined the bulk compositions of rocky planets around chemically diverse stars. our t - p - dependent chemical equilibrium model is based on a gibbs free energy minimisation. we derived condensation temperatures for solar system parameters with a simulation limited to the most common chemical species. we assessed their change ( $ \ delta t _ c $ ) as a result of p - variation between $ 10 ^ { - 6 } $ and 0. 1 bar. to analyse the influence of the abundance pattern, key element ratios were varied, and the results were validated using solar neighbourhood stars. to derive the bulk compositions of planets, we explored three different planetary feeding - zone ( fz ) models and compared their output to an external n - body simulation. our model reproduces the external results well in all tests. for common planet - building elements, we derive a tc that is within $ \ pm5 $ k of literature values, taking a wider spectrum of components into account. the tc is sensitive to variations in p and the abundance pattern. for most elements, it rises with p and metallicity. the tested pressure range ( $ 10 ^ { - 6 } - 0. 1 $ bar ) corresponds to $ \ delta t _ c \ approx + 350 $ k, and for - 0. 3 $ \ leq $ [ m / h ] $ \ leq $ 0. 4 we find $ \ delta t _ c \ approx + 100 $ k. an increase in c / o from 0. 1 to 0. 7 results in a decrease of $ \ delta t _ c \ approx - 100 $ k. other element ratios are less influential. dynamic planetary accretion can be emulated well with any fz model. their width can be adapted to reproduce gradual changes in planetary composition.
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arxiv:2307.00914
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this paper studies a new maximal operator introduced by hyt \ " onen, mcintosh and portal in 2008 for functions taking values in a banach space. the l ^ p - boundedness of this operator depends on the range space ; certain requirements on type and cotype are present for instance. the original euclidean definition of the maximal function is generalized to sigma - finite measure spaces with filtrations and the l ^ p - boundedness is shown not to depend on the underlying measure space or the filtration. martingale techniques are applied to prove that a weak type inequality is sufficient for l ^ p - boundedness and also to provide a characterization by concave functions.
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arxiv:0912.3358
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we present the first images of the 28sio v = 1, j = 2 - 1 maser emission around the closest known massive young stellar object orion source i observed at 86 ghz ( 3mm ) with the vlba. these images have high spatial ( ~ 0. 3 mas ) and spectral ( ~ 0. 054 km / s ) resolutions. we find that the 3mm masers lie in an x - shaped locus consisting of four arms, with blue - shifted emission in the south and east arms and red - shifted emission in the north and west arms. comparisons with previous images of the 28sio v = 1, 2, j = 1 - 0 transitions at 7mm ( observed in 2001 - 2002 ) show that the bulk of the j = 2 - 1 transition emission follows the streamlines of the j = 1 - 0 emission and exhibits an overall velocity gradient consistent with the gradient at 7mm. while there is spatial overlap between the 3mm and 7mm transitions, the 3mm emission, on average, lies at larger projected distances from source i ( ~ 44 au compared with ~ 35 au for 7mm ). the spatial overlap between the v = 1, j = 1 - 0 and j = 2 - 1 transitions is suggestive of a range of temperatures and densities where physical conditions are favorable for both transitions of a same vibrational state. however, the observed spatial offset between the bulk of emission at 3mm and 7mm possibly indicates different ranges of temperatures and densities for optimal excitation of the masers. we discuss different maser pumping models that may explain the observed offset. we interpret the 3mm and 7mm masers as being part of a single wide - angle outflow arising from the surface of an edge - on disk rotating about a northeast - southwest axis, with a continuous velocity gradient indicative of differential rotation consistent with a keplerian profile in a high - mass proto - binary.
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arxiv:1707.07455
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in time reversal symmetric systems with half integral spins ( or more concretely, systems with an antiunitary symmetry that squares to - 1 and commutes with the hamiltonian ) the transmission eigenvalues of the scattering matrix come in pairs. we present a proof of this fact that is valid both for even and odd number of modes and relies solely on the antisymmetry of the scattering matrix imposed by time reversal symmetry.
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arxiv:0805.3232
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in complex dynamics, the bungee set is defined as the set points whose orbit is neither bounded nor tends to infinity. in this paper we study, for the first time, the bungee set of a quasiregular map of transcendental type. we show that this set is infinite, and shares many properties with the bungee set of a transcendental entire function. by way of contrast, we give examples of novel properties of this set in the quasiregular setting. in particular, we give an example of a quasiconformal map of the plane with a non - empty bungee set ; this behaviour is impossible for an analytic homeomorphism.
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arxiv:1803.01716
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even require a and b to be member of an ordered set. in engineering sciences, less formal use of the notation is to state that one quantity is " much greater " than another, normally by several orders of magnitude. the notation a b means that a is much less than b. the notation a b means that a is much greater than b. this implies that the lesser value can be neglected with little effect on the accuracy of an approximation ( such as the case of ultrarelativistic limit in physics ). in all of the cases above, any two symbols mirroring each other are symmetrical ; a < b and b > a are equivalent, etc. = = properties on the number line = = inequalities are governed by the following properties. all of these properties also hold if all of the non - strict inequalities ( ≤ and ≥ ) are replaced by their corresponding strict inequalities ( < and > ) and — in the case of applying a function — monotonic functions are limited to strictly monotonic functions. = = = converse = = = the relations ≤ and ≥ are each other ' s converse, meaning that for any real numbers a and b : = = = transitivity = = = the transitive property of inequality states that for any real numbers a, b, c : if either of the premises is a strict inequality, then the conclusion is a strict inequality : = = = addition and subtraction = = = a common constant c may be added to or subtracted from both sides of an inequality. so, for any real numbers a, b, c : in other words, the inequality relation is preserved under addition ( or subtraction ) and the real numbers are an ordered group under addition. = = = multiplication and division = = = the properties that deal with multiplication and division state that for any real numbers, a, b and non - zero c : in other words, the inequality relation is preserved under multiplication and division with positive constant, but is reversed when a negative constant is involved. more generally, this applies for an ordered field. for more information, see § ordered fields. = = = additive inverse = = = the property for the additive inverse states that for any real numbers a and b : = = = multiplicative inverse = = = if both numbers are positive, then the inequality relation between the multiplicative inverses is opposite of that between the original numbers. more specifically, for any non - zero real numbers a and b that are both positive (
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https://en.wikipedia.org/wiki/Inequality_(mathematics)
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an important feature of pervasive, intelligent assistance systems is the ability to dynamically adapt to the current needs of their users. hence, it is critical for such systems to be able to recognize those goals and needs based on observations of the user ' s actions and state of the environment. in this work, we investigate the application of two state - of - the - art, planning - based plan recognition approaches in a real - world setting. so far, these approaches were only evaluated in artificial settings in combination with agents that act perfectly rational. we show that such approaches have difficulties when used to recognize the goals of human subjects, because human behaviour is typically not perfectly rational. to overcome this issue, we propose an extension to the existing approaches through a classification - based method trained on observed behaviour data. we empirically show that the proposed extension not only outperforms the purely planning - based - and purely data - driven goal recognition methods but is also able to recognize the correct goal more reliably, especially when only a small number of observations were seen. this substantially improves the usefulness of hybrid goal recognition approaches for intelligent assistance systems, as recognizing a goal early opens much more possibilities for supportive reactions of the system.
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arxiv:2301.05608
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few - layer selenium and tellurium films have been recently prepared, and they provide a new platform to explore novel properties of two - dimensional ( 2d ) elemental materials. in this work, we have performed a systematic first - principles study on the electronic, linear, and nonlinear optical ( nlo ) properties of atomically thin selenium and tellurium films within the density - functional theory with the generalized gradient approximation plus scissors correction using the band gaps from the relativistic hybrid heyd - scuseria - ernzerhof functional calculations. interestingly, we find that few - layer se and te possess large second - harmonic generation ( shg ), linear electro - optic effect, and bulk photovoltaic effect. in particular, trilayer ( tl ) te possesses large shg coefficient, being more than 65 times larger than that of gan, a widely used nlo material. bilayer ( bl ) te has huge static shg coefficient, being more than 100 times larger than that of gan. furthermore, monolayer ( ml ) se possesses large shg coefficient. moreover, we predict that tl te exhibits strong bulk photovoltaic effect ( bpve ), being greater than that of ges, a polar system with the largest bpve found so far. although the shift current conductivities of bulk and 2d se are comparable, the shift current conductivities of tl te are five times larger than those of bulk te. finally, an analysis of the calculated electronic band structures indicates that the strong nlo responses of 2d se and te materials are primarily derived from their low - dimensional structures with high anisotropy, directional covalent bonding, lone - pair electrons, and relatively small band gaps. these findings provide a practical strategy to search for excellent nlo and bpve materials.
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arxiv:2012.01124
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we present a review on the current state of publicly available datasets within the human action recognition community ; highlighting the revival of pose based methods and recent progress of understanding person - person interaction modeling. we categorize datasets regarding several key properties for usage as a benchmark dataset ; including the number of class labels, ground truths provided, and application domain they occupy. we also consider the level of abstraction of each dataset ; grouping those that present actions, interactions and higher level semantic activities. the survey identifies key appearance and pose based datasets, noting a tendency for simplistic, emphasized, or scripted action classes that are often readily definable by a stable collection of sub - action gestures. there is a clear lack of datasets that provide closely related actions, those that are not implicitly identified via a series of poses and gestures, but rather a dynamic set of interactions. we therefore propose a novel dataset that represents complex conversational interactions between two individuals via 3d pose. 8 pairwise interactions describing 7 separate conversation based scenarios were collected using two kinect depth sensors. the intention is to provide events that are constructed from numerous primitive actions, interactions and motions, over a period of time ; providing a set of subtle action classes that are more representative of the real world, and a challenge to currently developed recognition methodologies. we believe this is among one of the first datasets devoted to conversational interaction classification using 3d pose features and the attributed papers show this task is indeed possible. the full dataset is made publicly available to the research community at www. csvision. swansea. ac. uk / converse.
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arxiv:1511.05788
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this paper presents disc, a dataset of millimeter - wave channel impulse response measurements for integrated human activity sensing and communication. this is the first dataset collected with a software - defined radio testbed that transmits 60 ghz ieee 802 - 11ay - compliant packets and estimates the channel response including scattered signals off the moving body parts of subjects moving in an indoor environment. the provided data consists of three parts, for more than 2 hours of channel measurements with high temporal resolution ( 0. 27 ms inter - packet time ). disc contains the contribution of 7 subjects performing 5 different activities, and includes data collected from two distinct environments. unlike available radar - based millimeter - wave sensing datasets, our measurements are collected using uniform packet transmission times and sparse traffic patterns from real wi - fi deployments. we develop, train, and release open - source baseline algorithms based on disc to perform human sensing tasks. our results demonstrate that disc can serve as a multi - purpose benchmarking tool for machine learning - based human activity recognition, radio frequency gait analysis, and sparse sensing algorithms for next - generation integrated sensing and communications.
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arxiv:2306.09469
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we consider quantum systems composed of $ n $ qubits, and the family of all bell ' s correlation inequalities for two two - valued measurements per site. we show that if a $ n $ - qubit state $ \ rho $ violates any of these inequalities, then it is at least bipartite distillable. indeed there exists a link between the amount of bell ' s inequality violation and the degree of distillability. thus, we strengthen the interpretation of bell ' s inequalities as detectors of useful entanglement.
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arxiv:quant-ph/0112102
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we consider a macroscopic two - sate system based on persistent current states of a bose - einstein condensate ( bec ) of interacting neutral atoms confined in a ring with a weak josephson link. we demonstrate that macroscopic superpositions of different bec flows are energetically favorable in this system. moreover, a macroscopic two - state dynamics emerges in the low energy limit. we also investigate fundamental limitations due to the noise inherent to the interacting bec of josephson - ring geometry. we show that the coherent macroscopic dynamics is readily measurable for an experimentally accessible range of parameters.
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arxiv:1009.1901
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we introduce a method for securely delivering a set of messages to a group of clients over a broadcast erasure channel where each client is interested in a distinct message. each client is able to obtain its own message but not the others '. in the proposed method the messages are combined together using a special variant of random linear network coding. each client is provided with a private set of decoding coefficients to decode its own message. our method provides security for the transmission sessions against computational brute - force attacks and also weakly security in information theoretic sense. as the broadcast channel is assumed to be erroneous, the missing coded packets should be recovered in some way. we consider two different scenarios. in the first scenario the missing packets are retransmitted by the base station ( centralized ). in the second scenario the clients cooperate with each other by exchanging packets ( decentralized ). in both scenarios, network coding techniques are exploited to increase the total throughput. for the case of centralized retransmissions we provide an analytical approximation for the throughput performance of instantly decodable network coded ( idnc ) retransmissions as well as numerical experiments. for the decentralized scenario, we propose a new idnc based retransmission method where its performance is evaluated via simulations and analytical approximation. application of this method is not limited to our special problem and can be generalized to a new class of problems introduced in this paper as the cooperative index coding problem.
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arxiv:1305.1415
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we construct infinitely many families of monotone lagrangian tori in $ \ mathbb { r } ^ 6 $, no two of which are related by hamiltonian isotopies ( or symplectomorphisms ). these families are distinguished by the ( arbitrarily large ) numbers of families of maslov index 2 pseudo - holomorphic discs that they bound.
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arxiv:1407.3725
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one considers geometry with the intransitive equaivalence relation. such a geometry is a physical geometry, i. e. it is described completely by the world function, which is a half of the squared distance function. the physical geometry cannot be axiomatized, in general. it is obtained as a result of deformation of the proper euclidean geometry. class of physical geometries is more powerful, than the class of axiomatized geometries. the physical geometry admits one to describe such geometric properties as discreteness, granularity and limited divisibility. these properties are important in application to the space - time. they admits one to explain the discrimination properties of the space - time, which generate discrete parameters of elementary particles. mathematical formalism of a physical geometry is very simple. the physical geometry is formulated in geometrical terms ( in terms of points and world function ) without a use of means of description ( coordinate system, space dimension, manifold, etc. ).
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arxiv:0807.2034
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the purpose of this paper is to introduce the construction of a stochastic process called ` ` diffusion house - moving ' ' and to explore its properties. we study the weak convergence of diffusion bridges conditioned to stay between two curves, and we refer to this limit as diffusion house - moving. applying this weak convergence result, we give the sample path properties of diffusion house - moving.
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arxiv:2503.16912
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it has been conjectured that the algebraic crossing number of a link is uniquely determined in minimal braid representation. this conjecture is true for many classes of knots and links. the morton - franks - williams inequality gives a lower bound for braid index. and sharpness of the inequality on a knot type implies the truth of the conjecture for the knot type. we prove that there are infinitely many examples of knots and links for which the inequality is not sharp but the conjecture is still true. we also show that if the conjecture is true for k and l, then it is also true for the ( p, q ) - cable of k and for the connect sum of k and l.
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arxiv:0907.1019
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we prove a new characterization of metric sobolev spaces, in the spirit of brezis - - van schaftingen - - yung ' s asymptotic formula. a new feature of our work is that we do not need poincar \ ' e inequality which is a common tool in the literature. another new feature is that we find a direct link between brezis - - van schaftingen - - yung ' s asymptotic formula and cheeger ' s lipschitz differentiability.
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arxiv:2504.16657
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the charged multiplicity fluctuations in deep - inelastic scattering ( dis ) are investigated to test perturbative qcd and local parton hadron duality ( lphd ). the fluctuations were measured with the zeus detector at hera in restricted phase space domains in the current breit frame region. the measurements are compared to analytic pqcd + lphd predictions and qcd - based monte carlo models.
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arxiv:hep-ex/0106080
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we propose a new type of diffuse interface model describing the evolution of a tumor mass under the effects of a chemical substance ( e. g., a nutrient or a drug ). the process is described by utilizing the variables $ \ varphi $, an order parameter representing the local proportion of tumor cells, and $ \ sigma $, representing the concentration of the chemical. the order parameter $ \ varphi $ is assumed to satisfy a suitable form of the cahn - hilliard equation with mass source and logarithmic potential of flory - huggins type ( or generalizations of it ). the chemical concentration $ \ sigma $ satisfies a reaction - diffusion equation where the cross - diffusion term has the same expression as in the celebrated keller - segel model. in this respect, the model we propose represents a new coupling between the cahn - hilliard equation and a subsystem of the keller - segel model. we believe that, compared to other models, this choice is more effective in capturing the chemotactic effects that may occur in tumor growth dynamics ( chemically induced tumor evolution and consumption of nutrient / drug by tumor cells ). note that, in order to prevent finite time blowup of $ \ sigma $, we assume a chemical source term of logistic type. our main mathematical result is devoted to proving existence of weak solutions in a rather general setting that covers both the two - and three - dimensional cases. under more restrictive assumptions on coefficients and data, and in some cases on the spatial dimension, we prove various regularity results. finally, in a proper class of smooth solutions we show uniqueness and continuous dependence on the initial data in a number of significant cases.
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arxiv:2202.11007
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the temperature structure of protoplanetary disks provides an important constraint on where in the disks rocky planets like our own form. recent nonideal magnetohydrodynamical ( mhd ) simulations have shown that the internal joule heating associated with magnetically driven disk accretion is inefficient at heating the disk midplane. a disk temperature model based on the mhd simulations predicts that in a disk around a solar - mass young star, the water snow line can move inside the current earth ' s orbit within 1 myr after disk formation. however, the efficiency of the internal joule heating depends on the disk ' s ionization and opacity structures, both of which are governed by dust grains. in this study, we investigate these effects by combing the previous temperature model for magnetically accreting disks with a parameterized model for the grain size and vertical distribution. grain growth enhances the gas ionization fraction and thereby allows joule heating to occur closer to the midplane. however, growth beyond 10 $ \ rm \ mu m $ causes a decrease in the disk opacity, leading to a lower midplane temperature. the combination of these two effects results in the midplane temperature being maximized when the grain size is in the range 10 - 100 $ \ rm \ mu m $. grain growth to millimeter sizes can also delay the snow line ' s migration to the 1 au orbit by up to a few myr. we conclude that accounting for dust growth is essential for accurately modeling the snow line evolution and terrestrial planet formation in magnetically accreting protoplanetary disks.
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arxiv:2205.13511
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the agile gamma - ray satellite provides large sky exposure levels ( $ \ geq 10 ^ 9 $ cm $ ^ 2 $ s per year on the galactic plane ) with sensitivity peaking at $ e \ sim $ 100 mev where the bulk of pulsar energy output is typically released. its $ \ sim $ 1 $ \ mu $ s absolute time tagging capability makes it perfectly suited for the study of gamma - ray pulsars. agile collected a large number of gamma - ray photons from egret pulsars ( $ \ geq $ 40, 000 pulsed counts for vela ) in two years of observations unveiling new interesting features at sub - millisecond level in the pulsars ' high - energy light - curves, gamma - ray emission from pulsar glitches and pulsar wind nebulae. agile detected about 20 nearby and energetic pulsars with good confidence through timing and / or spatial analysis. among the newcomers we find pulsars with very high rotational energy losses, such as the remarkable psr b1509 - - 58 with a magnetic field in excess of 10 $ ^ { 13 } $ gauss, and psr j2229 + 6114 providing a reliable identification for the previously unidentified egret source 3eg 2227 + 6122. moreover, the powerful millisecond pulsar b1821 - - 24, in the globular cluster m28, is detected during a fraction of the observations.
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arxiv:1101.2125
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the spin - valve complex magnetoimpedance of symmetric ferromagnet / normal metal / ferromagnet junctions is investigated within the drift - diffusion ( standard ) model of spin injection. the ac magnetoresistance - - - the real part difference of the impedances of the parallel and antiparallel magnetization configurations - - - exhibits an overall damped oscillatory behavior, as an interplay of the diffusion and spin relaxation times. in wide junctions the ac magnetoresistance oscillates between positive and negative values, reflecting resonant amplification and depletion of the spin accumulation, while the line shape for thin tunnel junctions is predicted to be purely lorentzian. the ac spin - valve effect could be a technique to extract spin transport and spin relaxation parameters in the absence of a magnetic field and for a fixed sample size.
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arxiv:1111.7244
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code large language models ( code llms ) have excelled at tasks like code completion but often miss deeper semantics such as execution effects and dynamic states. this paper aims to bridge the gap between code llms ' reliance on static text data and the need for semantic understanding for complex tasks like debugging and program repair. we introduce a novel strategy, monologue reasoning, to train code llms to reason comprehensive semantics, encompassing high - level functional descriptions, local execution effects of individual statements, and overall input / output behavior, thereby linking static code text with dynamic execution states. we begin by collecting pyx, a clean python corpus of fully executable code samples with functional descriptions and test cases. we propose training code llms not only to write code but also to understand code semantics by reasoning about key properties, constraints, and execution behaviors using natural language, mimicking human verbal debugging, i. e., rubber - duck debugging. this approach led to the development of semcoder, a code llm with only 6. 7b parameters, which shows competitive performance with gpt - 3. 5 - turbo on code generation and execution reasoning tasks. semcoder achieves 79. 3 % on humaneval ( gpt - 3. 5 - turbo : 76. 8 % ), 63. 6 % on cruxeval - i ( gpt - 3. 5 - turbo : 50. 3 % ), and 63. 9 % on cruxeval - o ( gpt - 3. 5 - turbo : 59. 0 % ). we also study the effectiveness of semcoder ' s monologue - style execution reasoning compared to concrete scratchpad reasoning, showing that our approach integrates semantics from multiple dimensions more smoothly. finally, we demonstrate the potential of applying learned semantics to improve code llms ' debugging and self - refining capabilities. our data, code, and models are available at : https : / / github. com / arise - lab / semcoder.
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arxiv:2406.01006
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we investigate the phase diagram on temperature - chemical potential plane in the nambu - jona - lasinio model with the dimensional regularization. while the structure of the resulting diagram shows resemblance to the one in the frequently used cutoff regularization, some results of our study indicate striking difference between these regularizations. the diagram in the dimensional regularization exhibits strong tendency of the first order phase transition.
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arxiv:1202.5220
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despite the large number of studies focused on the characterisation of li - rich stars and understanding the mechanisms leading to such enrichment, their origin remains a mystery. magnetic activity, particularly the phenomena usually associated with it, and the li abundance ( a ( li ) ) of stars, are in general thought to be connected. as of today, however, just how they are connected is unclear. in this work, we study a sample of young but evolved intermediate - mass red giants that are inhabitants of open clusters where planets have been searched for. our aim is to use radial velocity ( rv ) and stellar activity indicator signals to look for relations between li abundances and stellar activity or variability. we explored how the standard deviation ( std ), peak - to - peak amplitude ( ptp ), mean, and median of typical stellar activity indicators ( bis, fwhm, $ t _ \ textrm { eff } $, and h $ \ alpha $ index ) change as a function of the li content of 82 red giants. furthermore, we computed weighted pearson correlation coefficients ( $ \ rho _ w $ ) between time series of rv measurements and the stellar activity indicators for the stars in our sample. to aid our results, we also studied generalized lomb - scargle periodograms ( glsp ) to capture possible significant periodic temporal variations in our data. our analysis indicates that the std and ptp of bis and fwhm, the mean and median of the h $ \ alpha $ index, and $ v \ sin ( i ) $ increase exponentially with a ( li ) in our sample of red giants. significant temporal variations and correlations between rvs and activity indicators also tend to be found preferentially for stars where high a ( li ) is observed. most of the li - rich stars in our sample either show strong correlations of rv with at least one of the stellar activity indicators or reveal significant periodic temporal variations in their glsps of stellar activity indicators that are consistent with those found for rv.
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arxiv:2406.12711
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this is a review of some of the interesting properties of the riemann zeta function.
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arxiv:1812.02574
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the magnetization processes in fe nano - systems are investigated using the numerical simulations based on classical magnetic dipole moment interactions. the domain energies are calculated from moment - moment interactions over whole systems using large scale computing resources. the results directly show most of basic magnetization phenomena. the barkhausen effects are represented with jumps and terraces of magnetization steps induced from external field changes of { \ delta } h.
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arxiv:1406.3688
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we search for hints to the origin and nature of compact stellar systems in the magnitude range of ultracompact dwarf galaxies in deep wide - field imaging data of the fornax cluster core. we visually investigate a large sample of 355 spectroscopically confirmed cluster members with v - band equivalent magnitudes brighter than - 10 mag for faint extended structures. our data reveal peculiar compact stellar systems, which appear asymmetric or elongated from their outer light distribution. we characterize the structure of our objects by quantifying their core concentration, as well as their outer asymmetry and ellipticity. for the brighter objects of our sample we also investigate their spatial and phase - space distribution within the cluster. we argue that the distorted outer structure alone that is seen for some of our objects, is not sufficient to decide whether these systems have a star cluster or a galaxy origin. however, we find that objects with low core concentration and high asymmetry ( or high ellipticity ) are primarily located at larger cluster - centric distances as compared to the entire sample. this supports the hypothesis that at least some of these objects may originate from tidally stripped galaxies.
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arxiv:1605.01261
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we introduce the metric space valued in partially ordered groups, and define the convergence of sequences and the multi - valued weak contractions, etc., on the space. we then establish endpoint theorems for the defined maps. our contributions extend the theory of cone metric space constructed by huang and zhang ( 2007 ) and some recent results on the fixed point and endpoint theory, such as the endpoint theorem given by amini - harandi ( 2010 ).
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arxiv:1406.0057
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