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We present a novel approach to kinetic theory modeling enabling the simulation of a generic, real gas presented by its corresponding equation of state. The model is based on mass, momentum and energy conservation, and unlike the lattice…

Fluid Dynamics · Physics 2020-02-25 Ehsan Reyhanian , Benedikt Dorschner , Ilya Karlin

In relativistic physics, angular momentum is paired with a lesser known conserved quantity, the "mass moment", which appears as the time-space components of the angular momentum tensor. Calculations of mass moment in electromagnetic and…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Samuel E. Gralla , Kunal Lobo , Hongji Wei

Developing a quantitative understanding of wave plasma processes in the lower ionosphere requires a reasonably accurate theoretical description of the underlying physical processes. For such highly collisional plasma environment as the…

Plasma Physics · Physics 2024-07-22 Y. S. Dimant

Many stochastic continuous-state dynamical systems can be modeled as probabilistic programs with nonlinear non-polynomial updates in non-nested loops. We present two methods, one approximate and one exact, to automatically compute, without…

Applications · Statistics 2025-01-03 Andrey Kofnov , Marcel Moosbrugger , Miroslav Stankovič , Ezio Bartocci , Efstathia Bura

With the aid of a Fermi-Walker chart associated with an orthonormal frame attached to a time-like curve in spacetime, a discussion is given of relativistic balance laws that may be used to construct models of massive particles with spin,…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Robin W. Tucker

A macroscopic model to describe the dynamics of ion transport in ion channels is the Poisson-Nernst-Planck(PNP) equations. In this paper, we develop a finite-difference method for solving PNP equations, which is second-order accurate in…

Numerical Analysis · Mathematics 2013-03-18 Allen Flavell , Michael Machen , Bob Eisenberg , Chun Liu , Xiaofan Li

Inspired by a recent hyperbolic regularization of Burnett's hydrodynamic equations [A. Bobylev, J. Stat. Phys. 124, 371 (2006)], we introduce a method to derive hyperbolic equations of linear hydrodynamics to any desired accuracy in Knudsen…

Statistical Mechanics · Physics 2007-06-13 M. Colangeli , I. V. Karlin , M. Kroger

We calculate reduced moments $\overline \xi_q$ of the matter density fluctuations, up to order $q=5$, from counts in cells produced by Particle--Mesh numerical simulations with scale--free Gaussian initial conditions. We use power--law…

Astrophysics · Physics 2009-10-22 F. Lucchin , S. Matarrese , A. L. Melott , L. Moscardini

We derive a second-order realizability-preserving scheme for moment models for linear kinetic equations. We apply this scheme to the first-order continuous and discontinuous models in slab and three-dimensional geometry derived in a…

Numerical Analysis · Mathematics 2021-07-13 Florian Schneider , Tobias Leibner

Kinetic simulations of collisionless (or weakly collisional) plasmas using the Vlasov equation are often infeasible due to high resolution requirements and the exponential scaling of computational cost with respect to dimension. Recently,…

Computational Physics · Physics 2022-10-12 Erika Ye , Nuno F. G. Loureiro

We consider a parameter dependent family of damped hyperbolic equations with interesting limit behavior: the system approaches steady states exponentially fast and for parameter to zero the solutions converge to that of a parabolic limit…

Numerical Analysis · Mathematics 2017-04-19 Herbert Egger , Thomas Kugler

We present the design of a multiscale parareal method for kinetic equations in the fluid dynamic regime. The goal is to reduce the cost of a fully kinetic simulation using a parallel in time procedure. Using the multiscale property of…

Numerical Analysis · Mathematics 2025-02-06 Tino Laidin , Thomas Rey

In Physica A vol 387(24) (2008) pp6079-6094 [1], a kinetic equation for gas flows was proposed that leads to a set of four macroscopic conservation equations, rather than the traditional set of three equations. The additional equation…

Mathematical Physics · Physics 2012-04-10 S. Kokou Dadzie , Jason M. Reese

In recent years, kinetic equations have been used to model many social phenomena. A key feature of these models is that transition rate kernels involve Dirac delta functions, which capture sudden, discontinuous state changes. Here, we study…

Numerical Analysis · Mathematics 2025-12-12 Yassin Bahid , Eduardo Corona , Nancy Rodriguez

In this tutorial, a derivation of magnetohydrodynamics (MHD) valid beyond the usual ideal gas approximation is presented. Non-equilibrium thermodynamics is used to obtain conservation equations and linear constitutive relations. When…

Plasma Physics · Physics 2025-04-21 Jarett LeVan , Scott Baalrud

We present a new formulation of the Einstein equations that casts them in an explicitly first order, flux-conservative, hyperbolic form. We show that this now can be done for a wide class of time slicing conditions, including maximal…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Carles Bona , Joan Masso , Edward Seidel , Joan Stela

We deal with a system of two coupled differential equations, describing the evolution of a first order phase transition. In particular, we have two non-linear parabolic equations: the first one is deduced from a balance law for entropy and…

Analysis of PDEs · Mathematics 2011-07-19 Manuela Girotti

An application of approximate transformation groups to study dynamics of a system with distinct time scales is discussed. The utilization of the Krylov-Bogoliubov-Mitropolsky method of averaging to find solutions of the Lie equations is…

Mathematical Physics · Physics 2015-06-03 Vladimir F. Kovalev

The elimination of a fast time scale from the Vlasov equation by Lie-transform methods is an important step in deriving a reduced Vlasov equation such as the drift-kinetic Vlasov equation or the gyrokinetic Vlasov equation. It is shown here…

Plasma Physics · Physics 2007-05-23 Alain J. Brizard

This work presents a formalism to derive field quantities and conservation laws from the atomistic using the theory of distributions as the mathematical tool. By defining temperature as a derived quantity as that in molecular kinetic theory…

Statistical Mechanics · Physics 2023-11-20 Youping Chen