Article
Mathematics, Applied
Mitia Duerinckx, Raphael Winter
Summary: The Lenard-Balescu equation is a fundamental description of the collisional process in a spatially homogeneous system of interacting particles, correcting the standard Landau equation by considering collective screening effects. However, the mathematical theory of the Lenard-Balescu equation, especially in the case of Coulomb interactions, has been largely unexplored. In this paper, we focus on smooth interactions and show how dynamical screening effects can be perturbatively handled, establishing global and local well-posedness properties close to and away from equilibrium, respectively, while also discussing the convergence to equilibrium and the validity of the Landau approximation.
ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS
(2023)
Article
Physics, Multidisciplinary
Lorenzo Caprini, Umberto Marini Bettolo Marconi, Rene Wittmann, Hartmut Loewen
Summary: This paper investigates the effects of a nonuniform motility landscape and an external confining field on the properties of active particles. The active Ornstein-Uhlenbeck particle (AOUP) model is used to derive analytical approximations for the steady-state probability distribution of position and velocity. The results show that the interplay of these two physical fields can generate complex emerging behavior.
Article
Mathematics, Applied
Christopher Henderson, Weinan Wang
Summary: We prove a Schauder estimate for kinetic Fokker-Planck equations that decouples the time, space, and velocity variables, allowing us to avoid a major technical issue. As an application, we deduce a weak-strong uniqueness result for the spatially inhomogeneous Landau equation.
DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS
(2023)
Article
Physics, Fluids & Plasmas
Louis Jose, Scott D. Baalrud
Summary: This study investigates the friction force experienced by a massive test charge in a strongly magnetized one-component plasma, showcasing novel transport properties using a generalized Boltzmann kinetic theory. It reveals that strong magnetization leads to additional transverse components in the friction force, impacting the trajectory of the test charge significantly. The theory shows good agreement with recent molecular dynamics simulations and presents new insights into the effects of strong magnetization on plasma dynamics.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Fluids & Plasmas
T. Koide
Summary: In this study, we develop a systematic expansion method for the solution of the Fokker-Planck equation and obtain an alternative formula for the mean work in systems with degeneracy in the eigenvalues. By investigating the thermodynamic properties of symmetric and asymmetric deformation processes of a potential, we find that the critical time characterized by the relaxation time of the Fokker-Planck equation maximizes the difference between the two processes.
Article
Physics, Fluids & Plasmas
Upendra Harbola
Summary: Motivated by recent interest in stochastic resetting of a random walker, a generalized model is proposed in which the walker takes stochastic jumps of lengths proportional to its current position with certain probability. The model reveals rich stochastic dynamic behavior and a phase transition from a diffusive to a superdiffusive regime if the jumps of lengths that are twice (or more) of its current positions are allowed. This phase transition is accompanied by a reentrant diffusive behavior.
Article
Physics, Fluids & Plasmas
M. Pfeiffer, F. Garmirian, M. H. Gorji
Summary: Despite the significant disparity of collisional and macroscopic spatiotemporal scales, this study presents a novel numerical scheme for particle advection and collision treatment. The scheme offers attractive features for particle-based stochastic simulations and can be readily implemented to existing direct simulation Monte Carlo codes.
Article
Chemistry, Physical
Jiaji Zhang, Yoshitaka Tanimura
Summary: The paper presents an efficient approach to calculate the partition function of a system interacting with a heat bath. The approach utilizes the imaginary-time hierarchical equations of motion and differentiated elements with respect to the inverse temperature, allowing for accurate evaluation of the system, system-bath interaction, and heat-bath parts of the partition function.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Mathematics, Applied
Chao-Jiang Xu, Yan Xu
Summary: This study investigates the Cauchy problem of the spatially homogeneous fractional Kramers-Fokker-Planck equation and demonstrates that the solution exhibits Gevrey regularity and decay estimation with an L2 initial datum for positive time.
JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS
(2023)
Article
Optics
Clara Magnin, Laurene Quenot, Sylvain Bohic, Dan Mihai Cenda, Manuel Fernandez Martinez, Blandine Lantz, Bertrand Faure, Emmanuel Brun
Summary: This Letter demonstrates a simple, fast, and robust method for performing phase-contrast, dark-field, and directional dark-field imaging on a low-coherence laboratory system equipped with a conventional x ray tube.
Article
Physics, Multidisciplinary
Yuri S. Djikaev, Eli Ruckenstein, Mark Swihart
Summary: This study examines the validity of using the Fokker-Planck equation as an approximation to the kinetic equation of nucleation in multicomponent condensation. By analyzing the smallness of parameters, it is found that deviations from the Fokker-Planck equation can occur under certain conditions. Numerical calculations suggest that modifications to the conventional kinetic equation may be necessary for consistent comparison with experimental data.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Physics, Multidisciplinary
Chang Jiang, Chao Dong, Ding Li
Summary: Rutherford scattering is important in plasma transport, but the influence of magnetic field on it is still not well understood. In this study, we investigate electron-ion collisions transverse to a magnetic field and find that the scattering angle can be significantly influenced by the magnetic field. These results are important for interpreting experimental and theoretical results.
CHINESE PHYSICS LETTERS
(2022)
Article
Computer Science, Interdisciplinary Applications
Mathias Hoppe, Ola Embreus, Tunde Fulop
Summary: The study introduces a computationally efficient numerical tool for self-consistent simulations of plasma cooling and runaway electron dynamics during disruptions. It solves transport equations and kinetic equations, comparing electron dynamics resolved with different complexity levels.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Duxin Chen, Yongzheng Sun, Guanbo Shao, Wenwu Yu, Hai-Tao Zhang, Wei Lin
Summary: Investigated the mechanism governing the coordinated rotational flight of pigeon flocks, using sparse Bayesian learning method, revealed the decision-making process of rotational switching flight is more nonlinear, established a data-driven particle model with two potential wells and estimated the mean switching time for rotational direction.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Mathematics, Applied
Yue Zhong, Shaoyong Lai, Chunhua Hu
Summary: This article investigates the evolution of wealth distribution in a financial market using a dynamic exchange model. By embedding an appropriate value function, the investment strategies of agents are described. Experimental results show that wealth distribution will converge to a close lognormal distribution in the long run.
APPLIED MATHEMATICS AND COMPUTATION
(2021)
Article
Physics, Multidisciplinary
Xiaoyu Shi, Jian Zhang, Xia Jiang, Juan Chen, Wei Hao, Bo Wang
Summary: This study presents a novel framework using offline reinforcement learning to improve energy consumption in road transportation. By leveraging real-world human driving trajectories, the proposed method achieves significant improvements in energy consumption. The offline learning approach demonstrates generalizability across different scenarios.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Junhyuk Woo, Soon Ho Kim, Hyeongmo Kim, Kyungreem Han
Summary: Reservoir computing (RC) is a new machine-learning framework that uses an abstract neural network model to process information from complex dynamical systems. This study investigates the neuronal and network dynamics of liquid state machines (LSMs) using numerical simulations and classification tasks. The findings suggest that the computational performance of LSMs is closely related to the dynamic range, with a larger dynamic range resulting in higher performance.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Yuwei Yang, Zhuoxuan Li, Jun Chen, Zhiyuan Liu, Jinde Cao
Summary: This paper proposes an extreme learning machine (ELM) algorithm based on residual correction and Tent chaos sequence (TRELM-DROP) for accurate prediction of traffic flow. The algorithm reduces the impact of randomness in traffic flow through the Tent chaos strategy and residual correction method, and avoids weight optimization using the iterative method. A DROP strategy is introduced to improve the algorithm's ability to predict traffic flow under varying conditions.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Chengwei Dong, Min Yang, Lian Jia, Zirun Li
Summary: This work presents a novel three-dimensional system with multiple types of coexisting attractors, and investigates its dynamics using various methods. The mechanism of chaos emergence is explored, and the periodic orbits in the system are studied using the variational method. A symbolic coding method is successfully established to classify the short cycles. The flexibility and validity of the system are demonstrated through analogous circuit implementation. Various chaos-based applications are also presented to show the system's feasibility.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Viorel Badescu
Summary: This article discusses the maximum work extraction from confined particles energy, considering both reversible and irreversible processes. The results vary for different types of particles and conditions. The concept of exergy cannot be defined for particles that undergo spontaneous creation and annihilation. It is also noted that the Carnot efficiency is not applicable to the conversion of confined thermal radiation into work.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
P. M. Centres, D. J. Perez-Morelo, R. Guzman, L. Reinaudi, M. C. Gimenez
Summary: In this study, a phenomenological investigation of epidemic spread was conducted using a model of agent diffusion over a square region based on the SIR model. Two possible contagion mechanisms were considered, and it was observed that the number of secondary infections produced by an individual during its infectious period depended on various factors.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Zuan Jin, Minghui Ma, Shidong Liang, Hongguang Yao
Summary: This study proposes a differential variable speed limit (DVSL) control strategy considering lane assignment, which sets dynamic speed limits for each lane to attract vehicle lane-changing behaviors before the bottleneck and reduce the impact of traffic capacity drop. Experimental results show that the proposed DVSL control strategy can alleviate traffic congestion and improve efficiency.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Matthew Dicks, Andrew Paskaramoorthy, Tim Gebbie
Summary: In this study, we investigate the learning dynamics of a single reinforcement learning optimal execution trading agent when it interacts with an event-driven agent-based financial market model. The results show that the agents with smaller state spaces converge faster and are able to intuitively learn to trade using spread and volume states. The introduction of the learning agent has a robust impact on the moments of the model, except for the Hurst exponent, which decreases, and it can increase the micro-price volatility as trading volumes increase.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Zhouzhou Yao, Xianyu Wu, Yang Yang, Ning Li
Summary: This paper developed a cooperative lane-changing decision system based on digital technology and indirect reciprocity. By introducing image scoring and a Q-learning based reinforcement learning algorithm, drivers can continuously evaluate gains and adjust their strategies. The study shows that this decision system can improve driver cooperation and traffic efficiency, achieving over 50% cooperation probability under any connected vehicles penetration and traffic density, and reaching 100% cooperation probability under high penetration and medium to high traffic density.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Josephine Nanyondo, Henry Kasumba
Summary: This paper presents a multi-class Aw-Rascle (AR) model with area occupancy expressed in terms of vehicle class proportions. The qualitative properties of the proposed equilibrium velocity and the stability conditions of the model are established. The numerical results show the effect of proportional densities on the flow of vehicle classes, indicating the realism of the proposed model.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Oliver Smirnov
Summary: This study proposes a new method for simultaneously estimating the parameters of the 2D Ising model. The method solves a constrained optimization problem, where the objective function is a pseudo-log-likelihood and the constraint is the Hamiltonian of the external field. Monte Carlo simulations were conducted using models of different shapes and sizes to evaluate the performance of the method with and without the Hamiltonian constraint. The results demonstrate that the proposed estimation method yields lower variance across all model shapes and sizes compared to a simple pseudo-maximum likelihood.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Przemyslaw Chelminiak
Summary: The study investigates the first-passage properties of a non-linear diffusion equation with diffusivity dependent on the concentration/probability density through a power-law relationship. The survival probability and first-passage time distribution are determined based on the power-law exponent, and both exact and approximate expressions are derived, along with their asymptotic representations. The results pertain to diffusing particles that are either freely or harmonically trapped. The mean first-passage time is finite for the harmonically trapped particle, while it is divergent for the freely diffusing particle.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Hidemaro Suwa
Summary: The choice of transition kernel is crucial for the performance of the Markov chain Monte Carlo method. A one-parameter rejection control transition kernel is proposed, and it is shown that the rejection process plays a significant role in determining the sampling efficiency.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)
Article
Physics, Multidisciplinary
Xudong Wang, Yao Chen
Summary: This article investigates the joint influence of expanding medium and constant force on particle diffusion. By starting from the Langevin picture and introducing the effect of external force in two different ways, two models with different force terms are obtained. Detailed analysis and derivation yield the Fokker-Planck equations and moments for the two models. The sustained force behaves as a decoupled force, while the intermittent force changes the diffusion behavior with specific effects depending on the expanding rate of the medium.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2024)