Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044207
Melvin Dix, Thomas Lilienkamp, Stefan Luther, Ulrich Parlitz
{"title":"Influence of conduction heterogeneities on transient spatiotemporal chaos in cardiac excitable media.","authors":"Melvin Dix, Thomas Lilienkamp, Stefan Luther, Ulrich Parlitz","doi":"10.1103/PhysRevE.110.044207","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044207","url":null,"abstract":"<p><p>Life-threatening cardiac arrhythmias such as ventricular fibrillation are often based on chaotic spiral or scroll wave dynamics which can be self-terminating. In this work, we investigate the influence of conduction heterogeneities on the duration of such chaotic transients in generic models of excitable cardiac media. We observe that low and medium densities of heterogeneities extend the average transient lifetime, while at high densities very long transients, potentially persistent chaos, and periodic attractors occur.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044207"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.L042104
Carl Fredrik Berg, Muhammad Sahimi
{"title":"Relation between critical exponent of the conductivity and the morphological exponents of percolation theory.","authors":"Carl Fredrik Berg, Muhammad Sahimi","doi":"10.1103/PhysRevE.110.L042104","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.L042104","url":null,"abstract":"<p><p>A central unsolved problem in percolation theory over the past five decades has been whether there is a direct relationship between the critical exponents that characterize the power-law behavior of the transport properties near the percolation threshold, particularly the effective electrical conductivity σ_{e}, and the exponents that describe the morphology of percolation clusters. The problem is also relevant to the relation between the static exponents of percolation clusters and the critical dynamics of spin waves in dilute ferromagnets, the elasticity of gels and composite solids, hopping conductivity in semiconductors, solute transport in porous media, and many others. We propose an approach to address the problem by showing that the contributions to σ_{e} can be decomposed into several groups representing the structure of percolation networks, including their mass and tortuosity, as well as constrictivity that describes the fluctuations in the driving potential gradient along the transport paths. The decomposition leads to a relationship between the critical exponent t of σ_{e} and other percolation exponents in d dimensions, t/ν=(d-D_{bb})+2(D_{op}-1)+d_{C}, where ν, D_{bb}, D_{op}, and d_{C} are, respectively, the correlation length exponent, the fractal dimensions of the backbones and the optimal paths, and the exponent that characterizes the constrictivity. Numerical simulations in two and three dimensions, as well as analytical results in d=1 and d=6, the upper critical dimension of percolation, validate the relationship. We, therefore, believe that the solution to the 50-year-old problem has been derived.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4","pages":"L042104"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044143
J Talbot, C Antoine, P Claudin, E Somfai, T Börzsönyi
{"title":"Exploring noisy Jeffery orbits: A combined Fokker-Planck and Langevin analysis in two and three dimensions.","authors":"J Talbot, C Antoine, P Claudin, E Somfai, T Börzsönyi","doi":"10.1103/PhysRevE.110.044143","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044143","url":null,"abstract":"<p><p>The behavior of nonspherical particles in a shear flow is of significant practical and theoretical interest. These systems have been the object of numerous investigations since the pioneering work of Jeffery a century ago. His eponymous orbits describe the deterministic motion of an isolated, rodlike particle in a shear flow. Subsequently, the effect of adding noise was investigated. The theory has been applied to colloidal particles, macromolecules, anisometric granular particles, and most recently to microswimmers, for example, bacteria. We study the Jeffery orbits of elongated (uniaxial, prolate) particles subject to noise using Langevin simulations and a Fokker-Planck equation. We extend the analytical solution for infinitely thin needles (β=1) obtained by Doi and Edwards to particles with arbitrary shape factor (0≤β≤1) and validate the theory by comparing it with simulations. We examine the rotation of the particle around the vorticity axis and study the orientational order matrix. We use the latter to obtain scalar order parameters s and r describing nematic ordering and biaxiality from the orientational distribution function. The value of s (nematic ordering) increases monotonically with increasing Péclet number, while r (measure of biaxiality) displays a maximum value. From perturbation theory, we obtain simple expressions that provide accurate descriptions at low noise (or large Péclet numbers). We also examine the orientational distribution in the v-grad v plane and in the perpendicular direction. Finally, we present the solution of the Fokker-Planck equation for a strictly two-dimensional (2D) system. For the same noise amplitude, the average rotation speed of the particle in 3D is larger than in 2D.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044143"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.045001
Haruka Noguchi, Satoshi Yukawa
{"title":"Fracture process of composite materials in a spring network model.","authors":"Haruka Noguchi, Satoshi Yukawa","doi":"10.1103/PhysRevE.110.045001","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.045001","url":null,"abstract":"<p><p>We analyze a two-dimensional spring network model comprising breakable and unbreakable springs. Computer simulations showed this system to exhibit intermittent stress drops in a larger strain regime, and these stress drops resulted in ductilelike behavior. The scaling analysis reveals that the avalanche size distribution demonstrates a cutoff, depending on its internal structure. This study also investigates the relationship between cluster growth and stress drop, and we show that the amount of stress drop increases in terms of power law, corresponding to crack growth. The crack length distribution also demonstrates a cutoff depending on its internal structure. The results show that both the cluster growth-stress drop relationship and the crack size distribution are scaled by the quantity related to the internal structure, and the relevance of the exponent that scales the cluster growth-stress drop relationship to the exponent that scales crack size distribution is verified.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-2","pages":"045001"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044101
Sergei Fedotov, Dmitri V Alexandrov
{"title":"Model for random internalization of nanoparticles by cells.","authors":"Sergei Fedotov, Dmitri V Alexandrov","doi":"10.1103/PhysRevE.110.044101","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044101","url":null,"abstract":"<p><p>We propose a stochastic model for the internalization of nanoparticles by cells formulating cellular uptake as a compound Poisson process with a random probability of success. This is an alternative approach to the one presented by Rees et al. [Nat. Commun. 10, 2341 (2019)2041-172310.1038/s41467-018-07882-8] who explained overdispersion in nanoparticle uptake and associated negative binomial distribution by considering a Poisson distribution for particle arrival and a gamma-distributed cell area. In our stochastic model, the formation of new pits is represented by the Poisson process, whereas the capturing process and the population heterogeneity are described by a random Bernoulli process with a beta-distributed probability of success. The random probability of success generates ensemble-averaged conditional transition probabilities that increase with the number of newly formed pits (self-reinforcement). As a result, an ensemble-averaged nanoparticle uptake can be represented as a Polya process. We derive an explicit formula for the distribution of the random number of pits containing nanoparticles. In the limit of the fast nucleation and low probability of nanoparticle capture, we find the negative binomial distribution.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044101"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044124
M Hernández-Sánchez, G Tapia-Labra, J A Méndez-Bermúdez
{"title":"Non-Hermitian diluted banded random matrices: Scaling of eigenfunction and spectral properties.","authors":"M Hernández-Sánchez, G Tapia-Labra, J A Méndez-Bermúdez","doi":"10.1103/PhysRevE.110.044124","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044124","url":null,"abstract":"<p><p>Here we introduce the non-Hermitian diluted banded random matrix (nHdBRM) ensemble as the set of N×N real nonsymmetric matrices whose entries are independent Gaussian random variables with zero mean and variance one if |i-j|<b and zero otherwise, moreover off-diagonal matrix elements within the bandwidth b are randomly set to zero such that the sparsity α is defined as the fraction of the N(b-1)/2 independent nonvanishing off-diagonal matrix elements. By means of a detailed numerical study we demonstrate that the eigenfunction and spectral properties of the nHdBRM ensemble scale with the parameter x=γ[(bα)^{2}/N]^{δ}, where γ,δ∼1. Moreover, the normalized localization length β of the eigenfunctions follows a simple scaling law: β=x/(1+x). For comparison purposes, we also report eigenfunction and spectral properties of the Hermitian diluted banded random matrix ensemble.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044124"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044311
Gianmarco Tiddia, Luca Sergi, Bruno Golosio
{"title":"Theoretical framework for learning through structural plasticity.","authors":"Gianmarco Tiddia, Luca Sergi, Bruno Golosio","doi":"10.1103/PhysRevE.110.044311","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044311","url":null,"abstract":"<p><p>A growing body of research indicates that structural plasticity mechanisms are crucial for learning and memory consolidation. Starting from a simple phenomenological model, we exploit a mean-field approach to develop a theoretical framework of learning through this kind of plasticity, capable of taking into account several features of the connectivity and pattern of activity of biological neural networks, including probability distributions of neuron firing rates, selectivity of the responses of single neurons to multiple stimuli, probabilistic connection rules, and noisy stimuli. More importantly, it describes the effects of stabilization, pruning, and reorganization of synaptic connections. This framework is used to compute the values of some relevant quantities used to characterize the learning and memory capabilities of the neuronal network in training and testing procedures as the number of training patterns and other model parameters vary. The results are then compared with those obtained through simulations with firing-rate-based neuronal network models.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044311"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044123
Stefano Giordano, Ralf Blossey
{"title":"Effective diffusion constant of stochastic processes with spatially periodic noise.","authors":"Stefano Giordano, Ralf Blossey","doi":"10.1103/PhysRevE.110.044123","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044123","url":null,"abstract":"<p><p>We discuss the effective diffusion constant D_{eff} for stochastic processes with spatially dependent noise. Starting from a stochastic process given by a Langevin equation, different drift-diffusion equations can be derived depending on the choice of the discretization rule 0≤α≤1. We initially study the case of periodic heterogeneous diffusion without drift, and we determine a general result for the effective diffusion coefficient D_{eff}, which is valid for any value of α. We study the case of periodic sinusoidal diffusion in detail, and we find a relationship with Legendre functions. Then we derive D_{eff} for general α in the case of diffusion with periodic spatial noise and in the presence of a drift term, generalizing the Lifson-Jackson theorem. Our results are illustrated by analytical and numerical calculations on generic periodic choices for drift and diffusion terms.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044123"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044140
Mingzhong Lu, Sheng Fang, Zongzheng Zhou, Youjin Deng
{"title":"Interplay of the complete-graph and Gaussian fixed-point asymptotics in finite-size scaling of percolation above the upper critical dimension.","authors":"Mingzhong Lu, Sheng Fang, Zongzheng Zhou, Youjin Deng","doi":"10.1103/PhysRevE.110.044140","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044140","url":null,"abstract":"<p><p>For statistical mechanical systems with continuous phase transitions, there are two closely related but subtly different mean-field treatments, the Gaussian fixed point (GFP) in the renormalization group framework and the Landau mean-field theory or the complete-graph (CG) asymptotics. By large-scale Monte Carlo simulations, we systematically study the interplay of the GFP and CG effects to the finite-size scaling of percolation above the upper critical dimension d_{c}=6 with periodic and cylindrical boundary conditions. Our results suggest that, with periodic boundaries, the unwrapped correlation length scales as L^{d/6} at the critical point, diverging faster than L above d_{c}. As a consequence, the scaling behaviors of macroscopic quantities with respect to the linear system size L follow the CG asymptotics. The distance-dependent properties, such as the short-distance behavior of the two-point correlation function and the Fourier transformed quantities with nonzero modes, are still controlled by the GFP. With cylindrical boundaries, due to the interplay of the GFP and CG effects, the correlation length along the axial direction of the cylinder scales as ξ_{L}∼L^{(d-1)/5} within the critical window of size O(L^{-2(d-1)/5}), distinct from periodic boundary. A field-theoretical calculation for deriving the scaling of ξ_{L} is also presented. Moreover, the one-point surface correlation function along the axial direction of the cylinder is observed to scale as τ^{(1-d)/2} when the distance τ is short, but then enter a plateau of order L^{-3(d-1)/5} before it decays significantly fast.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044140"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Physical Review EPub Date : 2024-10-01DOI: 10.1103/PhysRevE.110.044301
Shan Liu, Hanfei Zhao
{"title":"Multivariate opinion evolution analysis on individual opinion differences: An agent-based model.","authors":"Shan Liu, Hanfei Zhao","doi":"10.1103/PhysRevE.110.044301","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044301","url":null,"abstract":"<p><p>The spiral of silence is a classic theory originating from the age of mass media, which posits that individuals may suppress dissenting opinions to avoid social exclusion. In the digital era, despite the persistence of this phenomenon, the rise of social media has catalyzed the emergence of an antispiral of silence-a counterphenomenon fueled by growing self-awareness and online anonymity. In this paper, we focus on an interesting phenomenon: how these two spirals compete with each other to promote pluralism in social networks. To this end, we propose the spiral competition model (SCM) to quantify the two spirals and explore the impact of this phenomenon on the evolution of public opinion. In the SCM, agents can generate pseudo-opinions as well as antiopinions. In addition, we propose a time-varying network topology updating algorithm based on triangle closure, which simulates the fluid nature of social connections. Furthermore, we propose a community-based opinion initialization method with Gaussian distribution for enhancing simulation fidelity. Finally, we applied complex network theory to information dissemination, and the model was then simulated and analyzed in Erdős-Rényi random networks. And the rationality of SCM was verified using Sina Weibo data. The experimental results show that while the spiral of silence initially holds sway, the antispiral of silence can precipitate significant opinion divergence during critical junctures, challenging the status quo. And if the antispiral of silence fails to prevail, the trend of public opinion will be difficult to reverse. This research helps us recognize the influence that can be brought about by the awakening of individual consciousness, and provides an important reference for public opinion prediction.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044301"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}