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A dynamical system framework is used to describe transport processes in plasmas embedded in a magnetic field. For periodic systems with one degree of freedom the Poincar\'e map provides a splitting of the phase space into regions where…

Plasma Physics · Physics 2015-07-28 M. V. Falessi , F. Pegoraro , T. J. Schep

Numerical transport models based on the advection-dispersion equation (ADE) are built on the assumption that sub-grid cell transport is Fickian such that dispersive spreading around the average velocity is symmetric and without significant…

Geophysics · Physics 2017-03-30 Boris Baeumer , Yong Zhang , Rina Schumer

We study transport in a model perturbed integrable Hamiltonian system by calculating the volume, V(t), of elementary phase space cells visited by a trajectory, as a function of time. We use this function in order to "measure" the fractality…

chao-dyn · Physics 2016-08-31 H. Varvoglis , Ch. Vozikis , B. Barbanis

Context: Typical space plasmas contain spatially and temporally variable turbulent electromagnetic fields. Understanding the transport of energetic particles and the acceleration mechanisms for charged particles is an important goal of…

High Energy Astrophysical Phenomena · Physics 2013-06-17 R. C. Tautz , I. Lerche , F. Kruse

We investigate a many-body localization transition based on a Boltzmann transport theory. Introducing weak localization corrections into a Boltzmann equation, Hershfield and Ambegaokar re-derived the Wolfle-Vollhardt self-consistent…

Disordered Systems and Neural Networks · Physics 2018-07-04 Jae-Ho Han , Ki-Seok Kim

We study energy transport in the paradigmatic Hamiltonian mean-field (HMF) model and other related long-range interacting models using molecular dynamics simulations. We show that energy diffusion in the HMF model is subdiffusive in nature,…

Statistical Mechanics · Physics 2017-10-13 Debarshee Bagchi

In this paper we investigate the transport of energetic particles in turbulent plasmas. A numerical approach is used to simulate the effect of the background plasma on the motion of energetic protons. The background plasma is in a…

High Energy Astrophysical Phenomena · Physics 2015-06-04 M. Wisniewski , F. Spanier , R. Kissmann

Diffusive transport of a particle in spatially correlated random energy landscape having exponential density of states has been considered. We exactly calculate the diffusivity in the nondispersive quasi-equilibrium transport regime and…

Disordered Systems and Neural Networks · Physics 2018-02-14 S. V. Novikov

The transport properties of a random velocity field with Kolmogorov spectrum and time correlations defined along Lagrangian trajectories are analyzed. The analysis is carried on in the limit of short correlation times, as a perturbation…

Chaotic Dynamics · Physics 2009-11-07 Piero Olla

We examine energy transport in an ensemble of closed quantum systems driven by stochastic perturbations. One can show that the probability and energy fluxes can be described in terms of quantum advection modes (QAM) associated with the…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 G. A. Levin , W. A. Jones , K. Walczak , K. L. Yerkes

Diffusion of self-propelled particles in the presence of randomly distributed obstacles in three dimensions is studied using molecular dynamics simulations. It is found that depending on the magnitude of the propelling force and the…

Soft Condensed Matter · Physics 2016-11-23 Hamidreza Khalilian , Hossein Fazli

Diffusion of particles through an heterogenous obstacle line is modeled as a two-dimensional diffusion problem with a one--directional nonlinear convective drift and is examined using two-scale asymptotic analysis. At the scale where the…

Analysis of PDEs · Mathematics 2018-04-24 Emilio N. M. Cirillo , Ida de Bonis , Adrian Muntean , Omar Richardson

We study an active random walker model in which a particle's motion is determined by a self-generated field. The field encodes information about the particle's path history. This leads to either self-attractive or self-repelling behavior.…

Statistical Mechanics · Physics 2009-11-11 R. Grima

The periodic Lorentz gas is a paradigmatic model to examine how macroscopic transport emerges from microscopic chaos. It consists of a triangular lattice of circular hard scatterers with a moving point particle. Recently this system became…

Statistical Mechanics · Physics 2019-05-30 S. Gil-Gallegos , R. Klages , J. Solanpää , E. Räsänen

The statistical properties of the $E \times B$ flux in different types of plasma turbulence simulations are investigated using probability density distribution functions (PDF). The physics included in the models ranges from two dimensional…

Plasma Physics · Physics 2009-11-10 Volker Naulin , Odd Erik Garcia , Anders Henry Nielsen , Jens Juul Rasmussen

Transport surrounding is full of all kinds of fields, like particle potential, external potential. Under these conditions, how elements work and how position and momentum redistribute in the diffusion? For enriching the Fick law in…

Soft Condensed Matter · Physics 2017-08-02 Jian-hui He , Jia-le Wen , Pei-rong Chen , Dong-qin Zheng , Wei-rong Zhong

We present a framework for systems in which diffusion-advection transport of a tracer substance in a mobile zone is interrupted by trapping in an immobile zone. Our model unifies different model approaches based on distributed-order…

Statistical Mechanics · Physics 2022-04-05 T. J. Doerries , A. V. Chechkin , R. Schumer , R. Metzler

We report a numerical study of Rayleigh--B\'enard convection through random porous media using pore-scale modelling, focusing on the Lagrangian dynamics of fluid particles and heat transfer for varied porosities $\phi$. Due to the…

Fluid Dynamics · Physics 2021-04-29 Shuang Liu , Linfeng Jiang , Cheng Wang , Chao Sun

In this paper, we address the motion of charged particles subjected to a discrete spectrum of electrostatic waves. We focus on situations when transport dominates, leading to significant variations in particle velocity. Nonetheless, these…

Plasma Physics · Physics 2025-10-23 Didier Bénisti

The way particles interact with turbulent structures, particularly in regions of high vorticity and strain rate, has been investigated in simulations of homogeneous turbulence and in simple flows which have a periodic or persistent…

Fluid Dynamics · Physics 2012-05-28 Michael W. Reeks