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We numerically study the diffusion and scattering of cosmic rays (CRs) together with their acceleration processes in the framework of the modern understanding of magnetohydrodynamic (MHD) turbulence. Based on the properties of compressible…

High Energy Astrophysical Phenomena · Physics 2023-11-17 Nana Gao , Jianfu Zhang

Cosmic Ray transport in curved background magnetic fields is investigated using numerical Monte-Carlo simulation techniques. Special emphasis is laid on the Solar system, where the curvature of the magnetic field can be described in terms…

High Energy Astrophysical Phenomena · Physics 2013-06-17 R. C. Tautz , A. Shalchi , A. Dosch

Cosmic rays (CRs) are a pivotal non-thermal component of galaxy formation and evolution. However, the intricacies of CR physics, particularly how they propagate in the circumgalactic medium (CGM), remain largely unconstrained. In this work,…

In this work we use the newly reported Boron-to-Carbon ratio (B/C) from AMS-02 and the time-dependent proton fluxes from PAMELA and AMS-02 to constrain the source and propagation parameters of cosmic rays in the Milky Way. A linear…

High Energy Astrophysical Phenomena · Physics 2017-05-03 Qiang Yuan , Su-Jie Lin , Kun Fang , Xiao-Jun Bi

We study the dynamics of a radioactive species flowing through a porous material, within the Continuous-Time Random Walk (CTRW) approach to the modelling of stochastic transport processes. Emphasis is given to the case where radioactive…

Statistical Mechanics · Physics 2008-05-17 A. Zoia

We consider the continuous time random walk model (CTRW) of tracer's motion in porous medium flows based on the experimentally determined distributions of pore velocity and pore size reported in Holzner et al. Phys. Rev. E 92, 013015…

Statistical Mechanics · Physics 2017-05-31 Itzhak Fouxon , Markus Holzner

The microphysics of ~GeV cosmic ray (CR) transport on galactic scales remain deeply uncertain, with almost all studies adopting simple prescriptions (e.g. constant-diffusivity). We explore different physically-motivated, anisotropic,…

High Energy Astrophysical Phenomena · Physics 2022-03-18 Philip F. Hopkins , Jonathan Squire , T. K. Chan , Eliot Quataert , Suoqing Ji , Dusan Keres , Claude-Andre Faucher-Giguere

A simple model for the nonlinear collective transport of interacting particles in a random medium with strong disorder is introduced and analyzed. A finite threshold for the driving force divides the behavior into two regimes characterized…

Condensed Matter · Physics 2009-10-28 Joe Watson , Daniel S. Fisher

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

Single-file transport refers to the motion of particles in a narrow channel, such that they cannot bypass each other. This constraint leads to strong correlations between the particles, described by correlation profiles, which measure the…

Statistical Mechanics · Physics 2024-02-09 Aurélien Grabsch , Théotim Berlioz , Pierre Rizkallah , Pierre Illien , Olivier Bénichou

Cosmic rays (CRs) with ~GeV energies can contribute significantly to the energy and pressure budget in the interstellar, circumgalactic, and intergalactic medium (ISM, CGM, IGM). Recent cosmological simulations have begun to explore these…

We present a field-theoretic framework to characterize the distribution of transmission eigenvalues for coherent wave propagation through disordered media. The central outcome is a transport equation for a matrix-valued radiance, analogous…

Mathematical Physics · Physics 2025-07-21 David Gaspard , Arthur Goetschy

Monte Carlo (MC) simulations of transport in random porous networks indicate that for high variances of the log-normal permeability distribution, the transport of a passive tracer is non-Fickian. Here we model this non-Fickian dispersion in…

Computational Physics · Physics 2018-08-01 Amir H. Delgoshaie , Patrick Jenny , Hamdi A. Tchelepi

In a recent paper (Moskalenko et al., 2002), it has been shown that the flux of secondary cosmic ray (CR) antiprotons appears to be contradictory to measurements of secondary to primary nuclei ratios in cosmic rays when calculated in the…

Astrophysics · Physics 2010-05-27 V. S. Ptuskin , I. V. Moskalenko , F. C. Jones , A. W. Strong , S. G. Mashnik

Understanding energy transport in semiconductors is critical for design of electronic and optoelectronic devices. Semiconductor material properties such as charge carrier mobility or diffusion length are commonly measured in bulk crystals…

The theory of first order Fermi acceleration at shocks assumes that particles diffuse due to scattering off slow-moving magnetic irregularities. However, cosmic rays are closely tied to magnetic field lines, and the transport process,…

Astrophysics · Physics 2011-05-23 P. Duffy , J. G. Kirk , Y. A. Gallant , R. O. Dendy

The paper numerically investigates the propagation of galactic cosmic rays in a model magnetic field, which is a composition of an isotropic turbulent field with the Kolmogorov turbulence spectrum and a regular constant field. The…

High Energy Astrophysical Phenomena · Physics 2024-11-08 V. O Yurovsky , A. I. Peryatinskaya , I. Kudryashov

We study the propagation of cosmic rays (CRs) through a simulation of magnetohydrodynamic (MHD) turbulence at unprecedented resolution of $10{,}240^3$. We drive turbulence that is subsonic and super-Alfv\'enic, characterized by $\delta…

The bulk propagation speed of GeV-energy cosmic rays is limited by frequent scattering off hydromagnetic waves. Most galaxy evolution simulations that account for this confinement assume the gas is fully ionized and cosmic rays are…

High Energy Astrophysical Phenomena · Physics 2021-06-09 Chad Bustard , Ellen G. Zweibel

Anomalous diffusion constitutes a relation between tracer flux and tracer density gradient that is inherently nonlocal in space and/or time. Previous studies emphasize the non-Gaussian character of the tracer distribution that arises from…

Statistical Mechanics · Physics 2014-12-31 Bjorn Vermeersch , Ali Shakouri
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