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A new fully discrete linearized $H^1$-conforming Lagrange finite element method is proposed for solving the two-dimensional magneto-hydrodynamics equations based on a magnetic potential formulation. The proposed method yields numerical…

Numerical Analysis · Mathematics 2019-03-12 Buyang Li , Jilu Wang , Liwei Xu

We describe in this article a new code for evolving axisymmetric isolated systems in general relativity. Such systems are described by asymptotically flat space-times which have the property that they admit a conformal extension. We are…

General Relativity and Quantum Cosmology · Physics 2009-11-07 J. Frauendiener , Matthias Hein

The standard paradigm of cosmology assumes General Relativity (GR) is a valid theory for gravity at scales in which it has not been properly tested. Developing novel tests of GR and its alternatives is crucial if we want to give strength to…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-22 Claudio Llinares

In this paper we present a numerical method for hydrodynamic models that arise from time dependent density functional theories of freezing. The models take the form of compressible Navier-Stokes equations whose pressure is determined by the…

Numerical Analysis · Mathematics 2016-01-20 Arvind Baskaran , Zhen Guan , John Lowengrub

We describe how analytic solutions for linear hydromagnetic waves can be used for testing cosmological magnetohydrodynamic (MHD) codes. We start from the comoving MHD equations and derive analytic solutions for the amplitude evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-03 Thomas Berlok

We have developed a new three-dimensional general relativistic magnetohydrodynamic (GRMHD) code, RAISHIN, using a conservative, high resolution shock-capturing scheme. The numerical fluxes are calculated using the Harten, Lax, & van Leer…

Astrophysics · Physics 2007-05-23 Yosuke Mizuno , Ken-Ichi Nishikawa , Shinji Koide , Philip Hardee , Gerald J. Fishman

We present a multi-block finite-difference solver for massively parallel Direct Numerical Simulations (DNS) of incompressible flows. The algorithm combines the versatility of a multi-block solver with the method of eigenfunctions…

Computational Physics · Physics 2022-09-14 Pedro Costa

A multigrid method is proposed for solving nonlinear eigenvalue problems by the finite element method. With this new scheme, solving nonlinear eigenvalue problem is decomposed to a series of solutions of linear boundary value problems on…

Numerical Analysis · Mathematics 2015-01-09 Hehu Xie

Numerical simulations of self-gravitating flows evolve a momentum equation and an energy equation that account for accelerations and gravitational energy releases due to a time-dependent gravitational potential. In this work, we implement a…

Instrumentation and Methods for Astrophysics · Physics 2021-02-17 P. D. Mullen , Tomoyuki Hanawa , C. F. Gammie

We describe a new hybrid N-body/hydrodynamical code based on the particle-mesh (PM) method and the piecewise-parabolic method (PPM) for use in solving problems related to the evolution of large-scale structure, galaxy clusters, and…

Astrophysics · Physics 2009-10-31 P. M. Ricker , S. Dodelson , D. Q. Lamb

It is now generally agreed that multidimensional, multigroup, radiation hydrodynamics is an indispensable element of any realistic model of stellar-core collapse, core-collapse supernovae, and protoneutron star instabilities. We have…

Astrophysics · Physics 2007-05-23 F. Douglas Swesty , Eric S. Myra

Hydrodynamics calculations have been successfully used in studies of the bulk properties of the Quark-Gluon Plasma, particularly of elliptic flow and shear viscosity. However, there are areas (for instance event-by-event simulations for…

This paper focuses on the numerical approximation of the linearized shallow water equations using hybridizable discontinuous Galerkin (HDG) methods, leveraging the Hamiltonian structure of the evolution system. First, we propose an…

Numerical Analysis · Mathematics 2025-07-04 C. Núñez , M. A. Sánchez

We present a novel homogeneous and geometrically flat exact solution of Einstein's General Relativity equations for an ideal fluid. The solution, which describes an expanding/contracting hypercylinder, fits well with the observational…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-05 David H. Oaknin

We present a description of the adaptive mesh refinement (AMR) implementation of the PLUTO code for solving the equations of classical and special relativistic magnetohydrodynamics (MHD and RMHD). The current release exploits, in addition…

High Energy Astrophysical Phenomena · Physics 2015-05-30 A. Mignone , C. Zanni , P. Tzeferacos , B. van Straalen , P. Colella , G. Bodo

We describe a numerical method for calculating the (3+1) dimensional general relativistic hydrodynamics of a coalescing neutron-star binary system. The relativistic field equations are solved at each time slice with a spatial 3-metric…

General Relativity and Quantum Cosmology · Physics 2008-12-18 J. R. Wilson , G. J. Mathews , P. Marronetti

This paper is to introduce a type of full multigrid method for the nonlinear eigenvalue problem. The main idea is to transform the solution of nonlinear eigenvalue problem into a series of solutions of the corresponding linear boundary…

Numerical Analysis · Mathematics 2016-11-03 Shanghui Jia , Hehu Xie , Manting Xie , Fei Xu

"Generalized Hydrodynamics" (GHD) stands for a model that describes one-dimensional \textit{integrable} systems in quantum physics, such as ultra-cold atoms or spin chains. Mathematically, GHD corresponds to nonlinear equations of kinetic…

Computational Physics · Physics 2023-11-21 Frederik Møller , Nicolas Besse , Igor E. Mazets , Hans-Peter Stimming , Norbert J. Mauser

We present a monolithic geometric multigrid preconditioner for solving fluid-solid interaction problems in Stokes limit. The problems are discretized by a spatially adaptive high-order meshless method, the generalized moving least squares…

Numerical Analysis · Mathematics 2022-09-07 Zisheng Ye , Xiaozhe Hu , Wenxiao Pan

Two new methods have been proposed for solving the gravitational constraints without using elliptic solvers by formulating them as either an algebraic-hyperbolic or parabolic-hyperbolic system. Here, we compare these two methods and present…

General Relativity and Quantum Cosmology · Physics 2018-08-28 István Rácz , Jeffrey Winicour