6,104 research outputs found
Modified Boltzmann Transport Equation and Freeze Out
We study Freeze Out process in high energy heavy ion reaction. The
description of the process is based on the Boltzmann Transport Equation (BTE).
We point out the basic limitations of the BTE approach and introduce Modified
BTE. The Freeze Out dynamics is presented in the 4-dimensional space-time in a
layer of finite thickness, and we employ Modified BTE for the realistic Freeze
Out description.Comment: 9 pages, 2 figure
Angular, spectral, and time distributions of highest energy protons and associated secondary gamma-rays and neutrinos propagating through extragalactic magnetic and radiation fields
The angular, spectral and temporal features of the highest energy protons and
accompanying them secondary neutrinos and synchrotron gamma-rays propagating
through the intergalactic magnetic and radiation fields are studied using the
analytical solutions of the Boltzmann transport equation obtained in the limit
of the small-angle and continuous-energy-loss approximation.Comment: 21 pages, 13 figure
Heat conduction in multifunctional nanotrusses studied using Boltzmann transport equation
Materials that possess low density, low thermal conductivity, and high
stiffness are desirable for engineering applications, but most materials cannot
realize these properties simultaneously due to the coupling between them.
Nanotrusses, which consist of hollow nanoscale beams architected into a
periodic truss structure, can potentially break these couplings due to their
lattice architecture and nanoscale features. In this work, we study heat
conduction in the exact nanotruss geometry by solving the frequency-dependent
Boltzmann transport equation using a variance-reduced Monte Carlo algorithm. We
show that their thermal conductivity can be described with only two parameters,
solid fraction and wall thickness. Our simulations predict that nanotrusses can
realize unique combinations of mechanical and thermal properties that are
challenging to achieve in typical materials
Fluid dynamical equations and transport coefficients of relativistic gases with non-extensive statistics
We derive equations for fluid dynamics from a non-extensive Boltzmann
transport equation consistent with Tsallis' non-extensive entropy formula. We
evaluate transport coefficients employing the relaxation time approximation and
investigate non-extensive effects in leading order dissipative phenomena at
relativistic energies, like heat conductivity, shear and bulk viscosity.Comment: 9 pages, 5 figures. Some small corrections in the text and in the
first figure caption; accepted for publication in Physical Review
- …