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We present a new magnetohydrodynamic (MHD) simulation code with the aim of providing accurate numerical solutions to astrophysical phenomena where discontinuities, shock waves, and turbulence are inherently important. The code implements…

Due to the prevalence of magnetic fields in astrophysical environments, magnetohydrodynamic (MHD) simulation has become a basic tool for studying astrophysical fluid dynamics. To further advance the precision of MHD simulations, we have…

High Energy Astrophysical Phenomena · Physics 2023-08-09 Jeongbhin Seo , Dongsu Ryu

The manuscript presents a new technique for computing the exponential of skew-Hermitian operators. Principal advantages of the proposed method include: stability even for large time-steps, the possibility to parallelize in time over many…

Numerical Analysis · Mathematics 2014-02-24 T. S. Haut , T. Babb , P. G. Martinsson , B. A. Wingate

This paper describes a multidimensional hydrodynamic code which can be used for studies of relativistic astrophysical flows. The code solves the special relativistic hydrodynamic equations as a hyperbolic system of conservation laws based…

Astrophysics · Physics 2009-11-13 Eunwoo Choi , Dongsu Ryu

We introduce a second-order, central-upwind finite volume method for the discretization of nonlinear hyperbolic conservation laws posed on the two-dimensional sphere. The semi-discrete version of the proposed method is based on a technique…

Analysis of PDEs · Mathematics 2015-12-29 Abdelaziz Beljadid , Philippe G. LeFloch

Recent advances in extreme image compression have revealed that mapping pixel data into highly compact latent representations can significantly improve coding efficiency. However, most existing methods compress images into 2-D latent spaces…

Computer Vision and Pattern Recognition · Computer Science 2025-11-17 Han Liu , Hengyu Man , Xingtao Wang , Wenrui Li , Debin Zhao

We consider hyperbolic systems of conservation laws with relaxation source terms leading to a diffusive asymptotic limit under a parabolic scaling. We introduce a new class of secondorder in time and space numerical schemes, which are…

Numerical Analysis · Mathematics 2022-05-23 Louis Reboul , Teddy Pichard , Marc Massot

In this work, we propose an asymptotic preserving scheme for a non-linear kinetic reaction-transport equation, in the regime of sharp interface. With a non-linear reaction term of KPP-type, a phenomenon of front propagation has been proved…

Numerical Analysis · Mathematics 2018-05-23 Hélène Hivert

Radiation hydrodynamics simulations based on the one-fluid two-temperature model may violate the law of energy conservation because the governing equations are expressed in a nonconservative formulation. Here, we maintain the important…

Plasma Physics · Physics 2018-03-09 Takashi Shiroto , Soshi Kawai , Naofumi Ohnishi

We present in this paper a multigroup model for radiation hydrodynamics to account for variations of the gas opacity as a function of frequency. The entropy closure model (M1) is applied to multigroup radiation transfer in a radiation…

High Energy Astrophysical Phenomena · Physics 2015-05-27 N. M. H. Vaytet , E. Audit , B. Dubroca , F. Delahaye

A wide range of physical phenomena exhibit auxiliary admissibility criteria, such as conservation of entropy or various energies, which arise implicitly under the exact solution of their governing PDEs. However, standard temporal schemes,…

Numerical Analysis · Mathematics 2024-01-29 Mohammad R. Najafian , Brian C. Vermeire

We present here RICH, a state of the art 2D hydrodynamic code based on Godunov's method, on an unstructured moving mesh (the acronym stands for Racah Institute Computational Hydrodynamics). This code is largely based on the code AREPO. It…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Almog Yalinewich , Elad Steinberg , Re'em Sari

We develop a time-dependent multi-group multidimensional relativistic radiative transfer code, which is required to numerically investigate radiation from relativistic fluids involved in, e.g., gamma-ray bursts and active galactic nuclei.…

Instrumentation and Methods for Astrophysics · Physics 2015-09-09 Nozomu Tominaga , Sanshiro Shibata , Sergei I. Blinnikov

CONTEXT: For more than two decades, stellar atmosphere codes have been used to derive the stellar and wind parameters of massive stars. Although they have become a powerful tool and sufficiently reproduce the observed spectral appearance,…

Solar and Stellar Astrophysics · Physics 2017-07-12 Andreas A. C. Sander , Wolf-Rainer Hamann , Helge Todt , Rainer Hainich , Tomer Shenar

Methods to solve the relativistic hydrodynamic equations are a key computational kernel in a large number of astrophysics simulations and are crucial to understanding the electromagnetic signals that originate from the merger of…

Instrumentation and Methods for Astrophysics · Physics 2015-12-02 Jackson DeBuhr , Bo Zhang , Matthew Anderson , David Neilsen , Eric W. Hirschmann

We conduct a numerical study of relativistic viscous fluid dynamics in the Density Frame for one-dimensional fluid flows. The Density Frame is a formulation of relativistic viscous hydrodynamics that is first-order in time, requires no…

We present a second-order formulation of multi-reference algebraic diagrammatic construction theory [Sokolov, A. Yu. J. Chem. Phys. 2018, 149, 204113] for simulating photoelectron spectra of strongly correlated systems (MR-ADC(2)). The…

Chemical Physics · Physics 2020-07-28 Koushik Chatterjee , Alexander Yu. Sokolov

The structure of steady plane-parallel radiative shock waves propagating through the hydrogen gas undergoing partial ionization and excitation of bound atomic states is investigated in terms of the self-consistent solution of the equations…

Astrophysics · Physics 2007-05-23 Yu. A. Fadeyev , D. Gillet

The prediction of complex dynamics remains an open problem across many domains of physics, where nonlinearities and multiscale interactions severely limit the reliability of conventional forecasting methods. Quantum reservoir computing…

Analysing two-dimensional shallow water equations with idealised bottom topographies have many applications in the atmospheric and oceanic sciences; however, restrictive flow pattern assumptions have been made to achieve explicit solutions.…

Fluid Dynamics · Physics 2023-05-01 Chang Liu , Antwan D. Clark