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We study a class of degenerate convection diffusion equations with a fractional nonlinear diffusion term. These equations are natural generalizations of anomalous diffusion equations, fractional conservations laws, local convection…

Analysis of PDEs · Mathematics 2011-07-28 Simone Cifani , Espen R. Jakobsen

We derive and implement a suitable boundary condition for the kinetic description of the electrons inside a plasma, which takes into account microphysical processes inside the wall. It is based on the surface scattering kernel, which…

Plasma Physics · Physics 2025-11-26 Felix Willert , Clemens Hoyer , Gordon K. Grubert , Franz X. Bronold

In this Master thesis we investigate the influence of pressure anisotropy and incompressible flow of arbitrary direction on the equilibrium properties of magnetically confined, axisymmetric toroidal plasmas. The main novel contribution is…

Plasma Physics · Physics 2016-08-16 Achilleas Evangelias

We present an investigation for the generation of intense magnetic fields in dense plasmas with an anisotropic electron Fermi-Dirac distribution. For this purpose, we use a new linear dispersion relation for transverse waves in the…

Plasma Physics · Physics 2015-05-13 F. Haas , P. K. Shukla , B. Eliasson

Diffusion of a penetrating liquid in a polymeric material does not often satisfy the classical diffusion equations and requires taking relaxational (viscoelastic) properties of the polymer into account. We investigate a boundary value…

Analysis of PDEs · Mathematics 2015-05-14 Dmitry A. Vorotnikov

Event horizon-scale observations of low-luminosity black hole accretion flows favor magnetically arrested disks, characterized by dynamically important magnetic fields ($\beta\lesssim1$, where $\beta$ is the ratio of plasma thermal pressure…

High Energy Astrophysical Phenomena · Physics 2026-03-10 Vedant Dhruv , Lorenzo Sironi , Jordy Davelaar , Aaron Tran

We present a positive and asymptotic preserving numerical scheme for solving linear kinetic, transport equations that relax to a diffusive equation in the limit of infinite scattering. The proposed scheme is developed using a standard…

Numerical Analysis · Mathematics 2018-07-18 M. Paul Laiu , Martin Frank , Cory D. Hauck

The boundary element method is an efficient algorithm for simulating acoustic propagation through homogeneous objects embedded in free space. The conditioning of the system matrix strongly depends on physical parameters such as density,…

Numerical Analysis · Mathematics 2021-12-07 Elwin van 't Wout , Seyyed R. Haqshenas , Pierre Gélat , Timo Betcke , Nader Saffari

Fusion research on magnetic confinement is confronted with a severe problem concerning the electron densities ne to be used in fusion devices. Indeed, high densities are mandatory for obtaining large efficiencies, whereas it is empirically…

Plasma Physics · Physics 2010-02-01 M. Zuin , A. Carati , M. Marino , E. Martines , L. Galgani

We prove the existence of strong time-periodic solutions and their asymptotic stability with the total energy of the perturbations decaying to zero at an exponential decay rate as $t \rightarrow \infty$ for a semilinear (nonlinearly…

Analysis of PDEs · Mathematics 2014-01-08 Jáuber C. Oliveira

We consider the equation $-\epsilon^{2}\Delta u + u = u^ {p}$ in a bounded domain $\Omega\subset\R^{3}$ with edges. We impose Neumann boundary conditions, assuming $1<p<5$, and prove concentration of solutions at suitable points of…

Analysis of PDEs · Mathematics 2015-05-20 Serena Dipierro

Fluid instabilities arise in a variety of contexts and are often unwanted results of engineering imperfections. In one particular model for a magnetized target fusion reactor, a pressure wave is propagated in a cylindrical annulus comprised…

Fluid Dynamics · Physics 2017-04-26 Michael Lindstrom

The equations describing planar magnetoacoustic waves of permanent form in a cold plasma are rewritten so as to highlight the presence of a naturally small parameter equal to the ratio of the electron and ion masses. If the magnetic field…

Plasma Physics · Physics 2021-05-07 G. Rowlands , M. A. Allen

We present a mathematical analysis of the asymptotic preserving scheme proposed in [M. Lemou and L. Mieussens, SIAM J. Sci. Comput., 31, pp. 334-368, 2008] for linear transport equations in kinetic and diffusive regimes. We prove that the…

Numerical Analysis · Mathematics 2009-10-06 Jian-Guo Liu , Luc Mieussens

This paper is concerned with the asymptotic stability of the solution to an initial-boundary value problem on the half line for a hyperbolic-elliptic coupled system of the radiating gas, where the data on the boundary and at the far field…

Analysis of PDEs · Mathematics 2021-07-12 Shanming Ji , Minyi Zhang , Changjiang Zhu

We consider the mixed Steklov-Neumann spectral problem for the modified Helmholtz equation in a bounded domain when the Steklov condition is imposed on a connected subset of the smooth boundary. In order to deduce the asymptotic behavior in…

Computational Physics · Physics 2025-07-22 Denis S. Grebenkov

The initial boundary value problem for a Cahn-Hilliard system subject to a dynamic boundary condition of Allen-Cahn type is treated. The vanishing of the surface diffusion on the dynamic boundary condition is the point of emphasis. By the…

Analysis of PDEs · Mathematics 2020-04-20 Pierluigi Colli , Takeshi Fukao

The dynamics of ionization fronts that generate a conducting body, are in simplest approximation equivalent to viscous fingering without regularization. Going beyond this approximation, we suggest that ionization fronts can be modeled by a…

Pattern Formation and Solitons · Physics 2009-11-11 B. Meulenbroek , U. Ebert , L. Schaefer

Using hybrid-kinetic particle-in-cell simulation, we study the evolution of an expanding, collisionless, magnetized plasma in which strong Alfv\'enic turbulence is persistently driven. Temperature anisotropy generated adiabatically by the…

High Energy Astrophysical Phenomena · Physics 2021-12-08 A. F. A. Bott , L. Arzamasskiy , M. W. Kunz , E. Quataert , J. Squire

In this paper, we study an asymptotic preserving (AP), energy stable and positivity preserving semi-implicit finite volume scheme for the Euler-Poisson-Boltzmann (EPB) system in the quasineutral limit. The key to energy stability is the…

Numerical Analysis · Mathematics 2024-08-16 K. R. Arun , R. Ghorai