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Ballistic propagation of a local impact in the onedimensional XY model J. Stat. Mech. (IF 2.215) Pub Date : 20210108
Atsuki YoshinagaLightconelike propagation of information is a universal phenomenon of nonequilibrium dynamics of integrable spin systems. In this paper, we investigate propagation of a local impact in the onedimensional XY model with the anisotropy γ in a magnetic field h by calculating the magnetization profile. Applying a local and instantaneous unitary operation to the ground state, which we refer to as the

Stationary properties of a nonMarkovian Brownian gyrator J. Stat. Mech. (IF 2.215) Pub Date : 20210108
Eduardo dos S Nascimento and Welles A M MorgadoWe investigate the stochastic behavior of a nonMarkovian version of an elementary Brownian gyrator. The model is defined by overdamped Langevinlike dynamics with a twodimensional harmonic potential that presents distinct principal axes and is coupled to heat baths at different temperatures. The thermal noises are assumed to be Gaussian, and are related to friction forces through a dissipation memory

Typical relaxation of perturbed quantum manybody systems J. Stat. Mech. (IF 2.215) Pub Date : 20210108
Lennart Dabelow and Peter ReimannWe substantially extend our relaxation theory for perturbed manybody quantum systems from ((2020) Phys. Rev. Lett. 124 120602) by establishing an analytical prediction for the timedependent observable expectation values which depends on only two characteristic parameters of the perturbation operator: its overall strength and its range or band width. Compared to the previous theory, a significantly

The phase diagram of ultra quantum liquids J. Stat. Mech. (IF 2.215) Pub Date : 20210108
Dam Thanh Son, Mikhail Stephanov and HoUng YeeWe discuss the dependence of the phase diagram of a hypothetical isotope of helium with nuclear mass less than 4 atomic mass units. We argue that with decreasing nucleus mass, the temperature of the superfluid phase transition (about 2.2 K in real 4 He) increases, while that of the liquid–gas critical point (about 5.2 K in real 4 He) decreases. We discuss various scenarios that may occur when the two

Asymptotic analysis of the elephant random walk J. Stat. Mech. (IF 2.215) Pub Date : 20210107
Cristian F Coletti and Ioannis PapageorgiouIn this work we study asymptotic properties of a long range memory random walk known as elephant random walk. First we prove recurrence and positive recurrence for the elephant random walk. Then, we establish the transience regime of the model. Finally, under the Poisson hypothesis, we study the replica mean field limit for this random walk and we obtain an upper bound for the expected distance of

Active Brownian particle in harmonic trap: exact computation of moments, and reentrant transition J. Stat. Mech. (IF 2.215) Pub Date : 20210107
Debasish Chaudhuri and Abhishek DharWe consider an active Brownian particle in a d dimensional harmonic trap, in the presence of translational diffusion. While the Fokker–Planck equation cannot in general be solved to obtain a closed form solution of the joint distribution of positions and orientations, as we show, it can be utilized to evaluate the exact time dependence of all moments, using a Laplace transform approach. We present

Optimization and growth in firstpassage resetting J. Stat. Mech. (IF 2.215) Pub Date : 20210106
B De Bruyne, J RandonFurling and S RednerWe combine the processes of resetting and first passage, resulting in firstpassage resetting , where the resetting of a random walk to a fixed position is triggered by the firstpassage event of the walk itself. In an infinite domain, firstpassage resetting of isotropic diffusion is nonstationary, and the number of resetting events grows with time according to ##IMG## [http://ej.iop.org/images/

Entanglement entropy of excited states in the quantum Lifshitz model J. Stat. Mech. (IF 2.215) Pub Date : 20210106
Juanfernando AngelRamelliIn this work we calculate the entanglement entropy of certain excited states of the quantum Lifshitz model (QLM). The QLM is a 2 + 1dimensional bosonic quantum field theory with an anisotropic scaling symmetry between space and time that belongs to the universality class of the quantum dimer model and its generalizations. The states we consider are constructed by exciting the eigenmodes of the Laplace–Beltrami

Disentanglement approach to quantum spin ground states: field theory and stochastic simulation J. Stat. Mech. (IF 2.215) Pub Date : 20210106
Stefano De NicolaWhile several tools have been developed to study the ground state of manybody quantum spin systems, the limitations of existing techniques call for the exploration of new approaches. In this manuscript we develop an alternative analytical and numerical framework for manybody quantum spin ground states, based on the disentanglement formalism. In this approach, observables are exactly expressed as

The phase diagram for a class of multispecies permissive asymmetric exclusion processes J. Stat. Mech. (IF 2.215) Pub Date : 20210106
Dipankar RoyIn this article, we investigate a multispecies generalization of the singlespecies asymmetric simple exclusion process defined on an open onedimensional lattice. We devise an exact projection scheme to find the phase diagram in terms of densities and currents of all species. In most of the phases, one or more species are absent in the system due to dynamical expulsion. We observe shocks as well in

Scaling domains in the nonequilibrium athermal random field Ising model of finite systems J. Stat. Mech. (IF 2.215) Pub Date : 20210106
Sanja Janićević, Dragica Knežević, Svetislav Mijatović and Djordje SpasojevićWe analyze the nonequilibrium athermal random field Ising model (RFIM) at equilateral cubic lattices of finite size L and show that the entire range of disorder consists of three distinct domains in which the model manifests different scaling behaviour. The first domain contains the values of disorder R that are below the critical disorder R c where the spanning avalanches almost surely appear when

Nonprobabilistic fermionic limit shapes J. Stat. Mech. (IF 2.215) Pub Date : 20210106
Saverio Bocini and JeanMarie StéphanWe study a translational invariant free fermions model in imaginary time, with nearest neighbor and nextnearest neighbor hopping terms, for a class of inhomogeneous boundary conditions. This model is known to give rise to limit shapes and arctic curves, in the absence of the nextnearest neighbor perturbation. The perturbation considered turns out to not be always positive, that is, the corresponding

Random matrix improved covariance estimation for a large class of metrics J. Stat. Mech. (IF 2.215) Pub Date : 20201223
Malik Tiomoko, Florent Bouchard, Guillaume Ginolhac and Romain CouilletRelying on recent advances in statistical estimation of covariance distances based on random matrix theory, this article proposes an improved covariance and precision matrix estimation method for a wide family of metrics. This method is shown to largely outperform the sample covariance matrix estimate and to compete with stateoftheart methods, while at the same time being computationally simpler

Universal statistics of Fisher information in deep neural networks: mean field approach J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Ryo Karakida, Shotaro Akaho and Shunichi AmariThe Fisher information matrix (FIM) is a fundamental quantity to represent the characteristics of a stochastic model, including deep neural networks (DNNs). The present study reveals novel statistics of FIM that are universal among a wide class of DNNs. To this end, we use random weights and large width limits, which enables us to utilize mean field theories. We investigate the asymptotic statistics

Gauges, loops, and polynomials for partition functions of graphical models J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Michael Chertkov, Vladimir Chernyak and Yury MaximovGraphical models represent multivariate and generally not normalized probability distributions. Computing the normalization factor, called the partition function, is the main inference challenge relevant to multiple statistical and optimization applications. The problem is #Phard that is of an exponential complexity with respect to the number of variables. In this manuscript, aimed at approximating

Generalized approximate survey propagation for highdimensional estimation J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Luca Saglietti, Yue M Lu and Carlo LucibelloIn generalized linear estimation (GLE) problems, we seek to estimate a signal that is observed through a linear transform followed by a componentwise, possibly nonlinear and noisy, channel. In the Bayesian optimal setting, generalized approximate message passing (GAMP) is known to achieve optimal performance for GLE. However, its performance can significantly degrade whenever there is a mismatch between

Belief propagation: accurate marginals or accurate partition function—where is the difference? J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Christian Knoll and Franz PernkopfWe analyze belief propagation on patch potential models—attractive models with varying local potentials—obtain all of the potentially many fixed points, and gather novel insights into belief propagation properties. In particular, we observe and theoretically explain several regions in the parameter space that behave fundamentally differently. We specify and elaborate on one specific region that, despite

Wide neural networks of any depth evolve as linear models under gradient descent J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Jaehoon Lee, Lechao Xiao, Samuel S Schoenholz, Yasaman Bahri, Roman Novak, Jascha SohlDickstein and Jeffrey PenningtonA longstanding goal in deep learning research has been to precisely characterize training and generalization. However, the often complex loss landscapes of neural networks (NNs) have made a theory of learning dynamics elusive. In this work, we show that for wide NNs the learning dynamics simplify considerably and that, in the infinite width limit, they are governed by a linear model obtained from the

Datadependence of plateau phenomenon in learning with neural network—statistical mechanical analysis J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Yuki Yoshida and Masato OkadaThe plateau phenomenon, wherein the loss value stops decreasing during the process of learning, has been reported by various researchers. The phenomenon was actively inspected in the 1990s and found to be due to the fundamental hierarchical structure of neural network models. Then, the phenomenon has been thought of as inevitable. However, the phenomenon seldom occurs in the context of recent deep

Dynamics of stochastic gradient descent for twolayer neural networks in the teacher–student setup J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Sebastian Goldt, Madhu S Advani, Andrew M Saxe, Florent Krzakala and Lenka ZdeborováDeep neural networks achieve stellar generalisation even when they have enough parameters to easily fit all their training data. We study this phenomenon by analysing the dynamics and the performance of overparameterised twolayer neural networks in the teacher–student setup, where one network, the student, is trained on data generated by another network, called the teacher. We show how the dynamics

Conformal symplectic and relativistic optimization J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Guilherme França, Jeremias Sulam, Daniel P Robinson and René VidalArguably, the two most popular accelerated or momentumbased optimization methods in machine learning are Nesterov’s accelerated gradient and Polyaks’s heavy ball, both corresponding to different discretizations of a particular second order differential equation with friction. Such connections with continuoustime dynamical systems have been instrumental in demystifying acceleration phenomena in optimization

Wide flat minima and optimal generalization in classifying highdimensional Gaussian mixtures J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Carlo Baldassi, Enrico M Malatesta, Matteo Negri and Riccardo ZecchinaWe analyze the connection between minimizers with good generalizing properties and high local entropy regions of a thresholdlinear classifier in Gaussian mixtures with the mean squared error loss function. We show that there exist configurations that achieve the Bayesoptimal generalization error, even in the case of unbalanced clusters. We explore analytically the errorcounting loss landscape in

Asymptotic learning curves of kernel methods: empirical data versus teacher–student paradigm J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Stefano Spigler, Mario Geiger and Matthieu WyartHow many training data are needed to learn a supervised task? It is often observed that the generalization error decreases as n − β where n is the number of training examples and β is an exponent that depends on both data and algorithm. In this work we measure β when applying kernel methods to real datasets. For MNIST we find β ≈ 0.4 and for CIFAR10 β ≈ 0.1, for both regression and classification tasks

Ultrametric fitting by gradient descent J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Giovanni Chierchia and Benjamin PerretWe study the problem of fitting an ultrametric distance to a dissimilarity graph in the context of hierarchical cluster analysis. Standard hierarchical clustering methods are specified procedurally, rather than in terms of the cost function to be optimized. We aim to overcome this limitation by presenting a general optimization framework for ultrametric fitting. Our approach consists of modeling the

Tractable minorfree generalization of planar zerofield Ising models J. Stat. Mech. (IF 2.215) Pub Date : 20201222
Valerii Likhosherstov, Yury Maximov and Michael ChertkovWe present a new family of zerofield Ising models over N binary variables/spins obtained by consecutive ‘gluing’ of planar and O (1)sized components and subsets of at most three vertices into a tree. The polynomial time algorithm of the dynamic programming type for solving exact inference (computing partition function) and exact sampling (generating i.i.d. samples) consists of sequential application

Thermodynamic asymmetries in dualtemperature Brownian dynamics J. Stat. Mech. (IF 2.215) Pub Date : 20201127
Neha Tyagi and Binny J CherayilRecent work by Cerasoli et al (2018 Phys. Rev. E 98 042149) on a twodimensional model of biased Brownian gyrators driven in part by temperature differences along distinct Cartesian axes, x and y , has revealed interesting asymmetries in the steadystate distribution of particle positions. These asymmetries are said to be reminiscent of the more conventional asymmetries associated with the fluctuation

Solving the spherical p spin model with the cavity method: equivalence with the replica results J. Stat. Mech. (IF 2.215) Pub Date : 20201127
Giacomo Gradenigo, Maria Chiara Angelini, Luca Leuzzi and Federico RicciTersenghiThe spherical p spin is a fundamental model for glassy physics, thanks to its analytical solution achievable via the replica method. Unfortunately, the replica method has some drawbacks: it is very hard to apply to diluted models and the assumptions beyond it are not immediately clear. Both drawbacks can be overcome by the use of the cavity method; however, this needs to be applied with care to spherical

Disentangling feature and lazy training in deep neural networks J. Stat. Mech. (IF 2.215) Pub Date : 20201127
Mario Geiger, Stefano Spigler, Arthur Jacot and Matthieu WyartTwo distinct limits for deep learning have been derived as the network width h → ∞, depending on how the weights of the last layer scale with h . In the neural tangent Kernel (NTK) limit, the dynamics becomes linear in the weights and is described by a frozen kernel Θ (the NTK). By contrast, in the meanfield limit, the dynamics can be expressed in terms of the distribution of the parameters associated

Random deposition with surface relaxation model in u v flower networks J. Stat. Mech. (IF 2.215) Pub Date : 20201127
Jin Min KimRandom deposition with a relaxation model in ( u , v ) flower networks is studied. In a (2, 2) flower network, the surface width W ( t , N ) was found to grow as b ln t in the early period and follows a ln N in the saturated regime, where t and N are the evolution time and the number of nodes in the network, respectively. The dynamic exponent z , obtained by the relation z = a / b , was z ≈ 2.11(10)

Parallel temperature interfaces in the Katz–Lebowitz–Spohn driven lattice gas J. Stat. Mech. (IF 2.215) Pub Date : 20201127
Ruslan I Mukhamadiarov, Priyanka and Uwe C TäuberWe explore a variant of the Katz–Lebowitz–Spohn (KLS) driven lattice gas in two dimensions, where the lattice is split into two regions that are coupled to heat baths with distinct temperatures. The geometry was arranged such that the temperature boundaries are oriented parallel to the external particle drive and resulting net current. We have explored the changes in the dynamical behavior that are

Runandtumble particles in two dimensions under stochastic resetting conditions J. Stat. Mech. (IF 2.215) Pub Date : 20201127
Ion Santra, Urna Basu and Sanjib SabhapanditWe study the effect of stochastic resetting on a runandtumble particle (RTP) in two spatial dimensions. We consider a resetting protocol which affects both the position and orientation of the RTP: the particle undergoes constantrate positional resetting to a fixed point in space and a random orientation. We compute the radial and x marginal stationarystate distributions and show that while the

Solutions for a hyperbolic diffusion equation with linear reaction terms J. Stat. Mech. (IF 2.215) Pub Date : 20201127
E K Lenzi, M K Lenzi, R S Zola and L R EvangelistaGeneral diffusion processes involve one or more diffusing species and are usually modelled by Fick’s law, which assumes infinite propagation velocity. In this article, searching for the effect of finite propagation speeds in a system with two reacting species, we investigate diffusing and reacting particles governed by a hyperbolic diffusion equation, that is, the Cattaneo equation, which describes

Degreeorderedpercolation on uncorrelated networks J. Stat. Mech. (IF 2.215) Pub Date : 20201117
Annalisa Caligiuri and Claudio CastellanoWe analyze the properties of degreeordered percolation (DOP), a model in which the nodes of a network are occupied in degreedescending order. This rule is the opposite of the much studied degreeascending protocol, used to investigate resilience of networks under intentional attack, and has received limited attention so far. The interest in DOP is also motivated by its connection with the suscep

Thermostatistics of a q deformed relativistic ideal Fermi gas J. Stat. Mech. (IF 2.215) Pub Date : 20201117
XuYang Hou, H Yan and Hao GuoIn this paper, we formulate a q deformed manybody theory for relativistic Fermi gas and discuss the effects of the deformation parameter q on physical properties of such systems. Since antiparticle excitations appear in the relativistic regime, a suitable treatment to the choice of deformation parameters for both fermions and antifermions must be carefully taken in order to get a consistent theory

Trafficinduced epidemic suppression in multiplex networks J. Stat. Mech. (IF 2.215) Pub Date : 20201117
Jie Chen, MaoBin Hu, YongHong Wu and Ming LiMultiplex networks have been proposed as an effective abstract of real complex systems, ranging from multimodal urban transportation systems to communication systems. In this paper, we investigate a trafficdriven epidemic model in multiplex networks, and derive a theoretical approach to accurately predict the epidemic threshold of each layer. Our results show that the multiplex structure can produce

Effect of local dissociations in bidirectional transport of driven particles J. Stat. Mech. (IF 2.215) Pub Date : 20201110
Akriti Jindal, Anatoly B Kolomeisky and Arvind Kumar GuptaMotivated by the complex processes of cellular transport when different types of biological molecular motors can move in opposite directions along protein filaments while also detaching from them, we developed a theoretical model of the bidirectional motion of driven particles. It utilizes a totally asymmetric simple exclusion process framework to analyze the dynamics of particles moving in opposite

Intermittent resetting potentials J. Stat. Mech. (IF 2.215) Pub Date : 20201110
Gabriel MercadoVásquez, Denis Boyer, Satya N Majumdar and Grégory SchehrWe study the nonequilibrium steady states (NESS) and first passage properties of a Brownian particle with position X subject to an external confining potential of the form V ( X )= μ  X , and that is switched on and off stochastically. Applying the potential intermittently generates a physically realistic diffusion process with stochastic resetting toward the origin, a topic which has recently attracted

Exploring the Gillis model: a discrete approach to diffusion in logarithmic potentials J. Stat. Mech. (IF 2.215) Pub Date : 20201110
Manuele Onofri, Gaia Pozzoli, Mattia Radice and Roberto ArtusoThe Gillis model, introduced more than 60 years ago, is a nonhomogeneous random walk with a positiondependent drift. Though parsimoniously cited both in physical and mathematical literature, it provides one of the very few examples of a stochastic system allowing for a number of exact results, although lacking translational invariance. We present old and novel results for this model, which moreover

Jamming of multiple persistent random walkers in arbitrary spatial dimension J. Stat. Mech. (IF 2.215) Pub Date : 20201103
M J Metson, M R Evans and R A BlytheWe consider the persistent exclusion process in which a set of persistent random walkers interact via hardcore exclusion on a hypercubic lattice in d dimensions. We work within the ballistic regime whereby particles continue to hop in the same direction over many lattice sites before reorienting. In the case of two particles, we find the mean firstpassage time to a jammed state where the particles

Area fluctuations on a subinterval of Brownian excursion J. Stat. Mech. (IF 2.215) Pub Date : 20201103
Baruch MeersonArea fluctuations of a Brownian excursion are described by the Airy distribution, which has found applications in different areas of physics, mathematics and computer science. Here we generalize this distribution to describe the area fluctuations on a subinterval of a Brownian excursion. In the first version of the problem (model 1) no additional conditions are imposed. In the second version (model

Counting statistics and microreversibility in stochastic models of transistors J. Stat. Mech. (IF 2.215) Pub Date : 20201103
Jiayin Gu and Pierre GaspardMultivariate fluctuation relations are established in several stochastic models of transistors, which are electronic devices with three ports and thus two coupled currents. For all these models, the transport properties are shown to satisfy Onsager’s reciprocal relations in the linear regime close to equilibrium as well as their generalizations holding in the nonlinear regimes farther away from equilibrium

Large scale analysis of generalization error in learning using margin based classification methods J. Stat. Mech. (IF 2.215) Pub Date : 20201103
Hanwen Huang and Qinglong YangLargemargin classifiers are popular methods for classification. We derive the asymptotic expression for the generalization error of a family of largemargin classifiers in the limit of both sample size n and dimension p going to ∞ with fixed ratio α = n / p . This family covers a broad range of commonly used classifiers including support vector machine, distance weighted discrimination, and penalized

A dynamical meanfield theory for learning in restricted Boltzmann machines J. Stat. Mech. (IF 2.215) Pub Date : 20201031
Burak Çakmak and Manfred OpperWe define a messagepassing algorithm for computing magnetizations in restricted Boltzmann machines, which are Ising models on bipartite graphs introduced as neural network models for probability distributions over spin configurations. To model nontrivial statistical dependencies between the spins’ couplings, we assume that the rectangular coupling matrix is drawn from an arbitrary birotation invariant

Biased measures for random constraint satisfaction problems: larger interaction range and asymptotic expansion J. Stat. Mech. (IF 2.215) Pub Date : 20201031
Louise Budzynski and Guilhem SemerjianWe investigate the clustering transition undergone by an exemplary random constraint satisfaction problem, the bicoloring of k uniform random hypergraphs, when its solutions are weighted nonuniformly, with a soft interaction between variables belonging to distinct hyperedges. We show that the threshold α d ( k ) for the transition can be further increased with respect to a restricted interaction

Universality of eigenvector delocalization and the nature of the SIS phase transition in multiplex networks J. Stat. Mech. (IF 2.215) Pub Date : 20201031
Guilherme Ferraz de Arruda, J A MéndezBermúdez, Francisco A Rodrigues and Yamir MorenoUniversal spectral properties of multiplex networks allow us to assess the nature of the transition between diseasefree and endemic phases in the SIS epidemic spreading model. In a multiplex network, depending on a coupling parameter, p , the inverse participation ratio (IPR) of the leading eigenvector of the adjacency matrix can be in two different structural regimes: (i) layerlocalized and (ii)

Quasistationary states in temporal correlations for traffic systems: Cologne orbital motorway as an example J. Stat. Mech. (IF 2.215) Pub Date : 20201031
Shanshan Wang, Sebastian Gartzke, Michael Schreckenberg and Thomas GuhrTraffic systems are complex systems that exhibit nonstationary characteristics. Therefore, the identification of temporary traffic states is significant. In contrast to the usual correlations of time series, here we study those of position series, revealing structures in time, i.e. the rich nonMarkovian features of traffic. Considering the traffic system of the Cologne orbital motorway as a whole

Glassy dynamics from generalized modecoupling theory: existence and uniqueness of solutions for hierarchically coupled integrodifferential equations J. Stat. Mech. (IF 2.215) Pub Date : 20201029
Rutger A Biezemans, Simone Ciarella, Onur Çaylak, Björn Baumeier and Liesbeth M C JanssenGeneralized modecoupling theory (GMCT) is a firstprinciplesbased and systematically correctable framework to predict the complex relaxation dynamics of glassforming materials. The formal theory amounts to a hierarchy of infinitely many coupled integrodifferential equations, which may be approximated using a suitable finiteorder closure relation. Although previous studies have suggested that finiteorder

Nearestneighbor functions for disordered stealthy hyperuniform manyparticle systems J. Stat. Mech. (IF 2.215) Pub Date : 20201029
Timothy M Middlemas and Salvatore TorquatoDisordered stealthy manyparticle systems in d dimensional Euclidean space ##IMG## [http://ej.iop.org/images/17425468/2020/10/103302/jstatabb8cbieqn1.gif] {${\mathbb{R}}^{d}$} are exotic amorphous states of matter that suppress any single scattering events for a finite range of wavenumbers around the origin in reciprocal space. They are currently the subject of intense fundamental and practical interest

Spatiotemporal dynamics of a predation system with time delay and spatial diffusion J. Stat. Mech. (IF 2.215) Pub Date : 20201028
Feng Rao, Junling Luo, Zhongliang Zhang and Yun KangThis paper investigates the spatiotemporal dynamics of a Monod–Haldane type predator–prey interaction system that incorporates: (1) a time delay in the predator response term in the predator equation; and (2) diffusion in both prey and predator. We provide rigorous results of our system including the asymptotic stability of equilibrium solutions and the existence and properties of Hopf bifurcations

Uncovering the dynamics of correlation structures relative to the collective market motion J. Stat. Mech. (IF 2.215) Pub Date : 20201027
Anton J Heckens, Sebastian M Krause and Thomas GuhrThe measured correlations of financial time series in subsequent epochs change considerably as a function of time. When studying the whole correlation matrices, quasistationary patterns, referred to as market states, are seen by applying clustering methods. They emerge, disappear or reemerge, but they are dominated by the collective motion of all stocks. In the jargon, one speaks of the market motion

Community enhancement network embedding based on edge reweighting preprocessing J. Stat. Mech. (IF 2.215) Pub Date : 20201027
Shaoqing Lv, Ju Xiang, Jingyu Feng, Honggang Wang, Guangyue Lu and Min LiNetwork embedding has attracted considerable attention in recent years. It represents nodes in a network into a lowdimensional vector space while keeping the properties of the network. Some methods (e.g. ComE, MNMF, and CARE) have been proposed to preserve the community property in network embedding, and they have obtained good results in some downstream network analysis tasks. However, there still

Joint distribution of multiple boundary local times and related firstpassage time problems with multiple targets J. Stat. Mech. (IF 2.215) Pub Date : 20201027
Denis S GrebenkovWe investigate the statistics of encounters of a diffusing particle with different subsets of the boundary of a confining domain. The encounters with each subset are characterized by the boundary local time on that subset. We extend a recently proposed approach to express the joint probability density of the particle position and of its multiple boundary local times via a multidimensional Laplace

Microscopic approach to the macrodynamics of matter with broken symmetries J. Stat. Mech. (IF 2.215) Pub Date : 20201023
Joël Mabillard and Pierre GaspardA unified set of hydrodynamic equations describing condensed phases of matter with broken continuous symmetries is derived using a generalization of the statisticalmechanical approach based on the local equilibrium distribution. The dissipativeless and dissipative parts of the current densities and the entropy production are systematically deduced in this approach by expanding in powers of the gradients

Maxwell–Boltzmann statistics of the quantum ideal gas in the canonical ensemble J. Stat. Mech. (IF 2.215) Pub Date : 20201022
Tyler Markham, JeongYoung Ji and Eric D HeldThe Maxwell–Boltzmann statistics of the quantum ideal gas is studied through the canonical partition function by exactly counting discrete quantum states without the continuum approximation. Analytic expressions for energy, pressure, entropy, and heat capacity are expressed in terms of Jacobi theta functions and complete elliptic integrals. The results show typical effects of discrete energy levels

Voronoi chains, blocks, and clusters in perturbed square lattices J. Stat. Mech. (IF 2.215) Pub Date : 20201022
Emanuel A Lazar and Amir ShoanPerturbed lattices provide simple models for studying many physical systems. In this paper we study the distribution of Voronoi chains, blocks, and clusters with prescribed combinatorial features in the perturbed square lattice, generalizing earlier work. In particular, we obtain analytic results for the presence of hexagonallyordered regions within a squareordered phase. Connections to hightemperature

Necessary and sufficient conditions for ##IMG## [http://ej.iop.org/images/17425468/2020/10/103202/toc_jstatabb6e0ieqn1.gif] {${\mathbb{Z}}_{2}$} symmetrybreaking phase transitions J. Stat. Mech. (IF 2.215) Pub Date : 20201011
Fabrizio BaroniIn a recent paper a toy model ( hypercubic model ) undergoing a firstorder ##IMG## [http://ej.iop.org/images/17425468/2020/10/103202/jstatabb6e0ieqn2.gif] {${\mathbb{Z}}_{2}$} symmetrybreaking phase transition ( ##IMG## [http://ej.iop.org/images/17425468/2020/10/103202/jstatabb6e0ieqn3.gif] {${\mathbb{Z}}_{2}$} SBPT) was introduced. The hypercubic model was inspired by the topological hypothesis

Entanglement Hamiltonians for noncritical quantum chains J. Stat. Mech. (IF 2.215) Pub Date : 20201011
Viktor Eisler, Giuseppe Di Giulio, Erik Tonni and Ingo PeschelWe study the entanglement Hamiltonian for finite intervals in infinite quantum chains for two different freeparticle systems: coupled harmonic oscillators and fermionic hopping models with dimerization. Working in the ground state, the entanglement Hamiltonian describes again free bosons or fermions and is obtained from the correlation functions via highprecision numerics for up to several hundred

Exact and asymptotic properties of δ records in the linear drift model J. Stat. Mech. (IF 2.215) Pub Date : 20201011
R Gouet, M Lafuente, F J López and G SanzThe study of records in the linear drift model (LDM) has attracted much attention recently due to applications in several fields. In the present paper we study δ records in the LDM, defined as observations which are greater than all previous observations, plus a fixed real quantity δ . We give analytical properties of the probability of δ records and study the correlation between δ record events

On the groundstate energy of the finite sineGordon ring J. Stat. Mech. (IF 2.215) Pub Date : 20201007
Sergei B RutkevichThe Casimir scaling function characterising the groundstate energy of the sineGordon model in a finite circle has been studied analytically and numerically both in the repulsive and attractive regimes. The numerical calculations of the scaling function at several values of the coupling constant were performed by the iterative solution of the Destri–de Vega nonlinear integral equations. The ultraviolet

Experimental study on pedestrians’ uni and bidirectional movement on staircases under emergency conditions J. Stat. Mech. (IF 2.215) Pub Date : 20201007
Jin Gao, Jinghai Gong, Jun He, Daxu Zhang, Guozhi Qiu and Jingjing ZhangStaircases are main vertical evacuation passages in multistory buildings characterized by different pedestrian flow from horizontal passages, such as corridors. Experiments were conducted to investigate crowd ascending and descending dynamics with different numbers of pedestrians in both uni and bidirectional scenarios. Evacuation processes were recorded by video cameras and velocity sensors, and