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We address the numerical treatment of source terms in algebraic flux correction schemes for steady convection-diffusion-reaction (CDR) equations. The proposed algorithm constrains a continuous piecewise-linear finite element approximation…

Numerical Analysis · Mathematics 2024-01-09 Petr Knobloch , Dmitri Kuzmin , Abhinav Jha

Equilibria in magnetic confinement devices result from force balancing between the Lorentz force and the plasma pressure gradient. In an axisymmetric configuration like a tokamak, such an equilibrium is described by an elliptic equation for…

Numerical Analysis · Mathematics 2025-06-13 Daniel A. Serino , Qi Tang , Xian-Zhu Tang , Tzanio V. Kolev , Konstantin Lipnikov

The purpose of the present paper is to provide an overview of Asymptotic-Preserving methods for multiscale plasma simulations by addressing three singular perturbation problems. First, the quasi-neutral limit of fluid and kinetic models is…

Plasma Physics · Physics 2017-04-05 Pierre Degond , Fabrice Deluzet

We study the Einstein-Maxwell system of equations in spherically symmetric gravitational fields for static interior spacetimes. The condition for pressure isotropy is reduced to a recurrence equation with variable, rational coefficients. We…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. Thirukkanesh , S. D. Maharaj

We introduce a new logotropic model based on a complex scalar field with a logarithmic potential that unifies dark matter and dark energy. The scalar field satisfies a nonlinear wave equation generalizing the Klein-Gordon equation in the…

General Relativity and Quantum Cosmology · Physics 2022-10-05 Pierre-Henri Chavanis

We consider the numerical approximation of the inertial Landau-Lifshitz-Gilbert equation (iLLG), which describes the dynamics of the magnetization in ferromagnetic materials at subpicosecond time scales. We propose and analyze two fully…

Numerical Analysis · Mathematics 2021-10-07 Michele Ruggeri

The aim of this work is to obtain new analitical solutions for Einstein equations in the anisotropical domain. This will be done via the minimal geometric deformation (MGD) approach, which is a simple and systematical method that allow us…

General Relativity and Quantum Cosmology · Physics 2018-08-21 C. Las Heras , P. Leon

Over-/under-break excavation is a common phenomenon in shallow tunnelling, which is nonetheless not generally considered in existing complex variable solutions. In this paper, a new equilibrium mechanical model on over-/under-break shallow…

Numerical Analysis · Mathematics 2024-04-16 Luo-bin Lin , Fu-quan Chen , Jin-ping Zhuang

This paper proposes a combination of a hybrid CPU--GPU and a pure GPU software implementation of a direct algorithm for solving shifted linear systems $(A - \sigma I)X = B$ with large number of complex shifts $\sigma$ and multiple…

Mathematical Software · Computer Science 2017-08-24 Nela Bosner , Zvonimir Bujanović , Zlatko Drmač

This paper resolves the global regularity problem for the three-dimensional incompressible magnetohydrodynamics (MHD) equations in the upper half-space with slip boundary conditions, in the presence of a background magnetic field. Motivated…

Analysis of PDEs · Mathematics 2025-08-14 Jincheng Gao , Lianyun Peng , Jiahong Wu , Zheng-an Yao

We study asymptotically constrained systems for numerical integration of the Einstein equations, which are intended to be robust against perturbative errors for the free evolution of the initial data. First, we examine the previously…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Gen Yoneda , Hisa-aki Shinkai

Many problems in Euclidean geometry, arising in computational design and fabrication, amount to a system of constraints, which is challenging to solve. We suggest a new general approach to the solution, which is to start with analogous…

Computational Geometry · Computer Science 2025-06-03 Khusrav Yorov , Bolun Wang , Mikhail Skopenkov , Helmut Pottmann , Caigui Jiang

Taking as starting point the planar model arising from the dimensional reduction of the Abelian-Higgs Carroll-Field-Jackiw model, we write down and study the extended Maxwell equations and the corresponding wave equations for the…

High Energy Physics - Theory · Physics 2011-09-13 H. Belich , T. Costa-Soares , M. M. Ferreira , J. A. Helayel-Neto

Liouvillian dynamics describes the evolution of a density operator in closed quantum systems. One extension towards open quantum systems is provided by the Lindblad equation. It is applied to various systems and energy regimes in solid…

Quantum Physics · Physics 2024-10-16 Jan Rais , Adrian Koenigstein , Niklas Zorbach , Carsten Greiner

This paper presents an asymptotic preserving (AP) all Mach number finite volume shock capturing method for the numerical solution of compressible Euler equations of gas dynamics. Both isentropic and full Euler equations are considered. The…

Numerical Analysis · Mathematics 2017-06-02 S. Boscarino , G. Russo , L. Scandurra

A recent third-order, essentially non-oscillatory central scheme to advance the equations of single-fluid magnetohydrodynamics (MHD) in time has been implemented into a new numerical code. This code operates on a 3-D Cartesian,…

Solar and Stellar Astrophysics · Physics 2012-04-18 Jens Kleimann , Andreas Kopp , Horst Fichtner , Rainer Grauer

In this article, we prove various illposedness results for the Cauchy problem for the incompressible Hall- and electron-magnetohydrodynamic (MHD) equations without resistivity. These PDEs are fluid descriptions of plasmas, where the effect…

Analysis of PDEs · Mathematics 2021-01-07 In-Jee Jeong , Sung-Jin Oh

Recent years have seen a significant progress in the development of general relativistic codes for the numerical solution of the equations of magnetohydrodynamics in spacetimes with high and dynamical curvature. These codes are valuable…

High Energy Astrophysical Phenomena · Physics 2024-04-23 Yosuke Mizuno , Luciano Rezzolla

This paper develops novel and robust central discontinuous Galerkin (CDG) schemes of arbitrarily high-order accuracy for special relativistic magnetohydrodynamics (RMHD) with a general equation of state (EOS). These schemes are provably…

Numerical Analysis · Mathematics 2024-02-26 Shengrong Ding , Kailiang Wu

This paper describes a numerical scheme for multi-fluid hydrodynamics in the limit of small mass densities of the charged particles. The inertia of the charged particles can then be neglected, which makes it possible to write an evolution…

Astrophysics · Physics 2009-11-10 S. A. E. G. Falle
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