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Related papers: Second Order Accurate Schemes for Magnetohydrodyna…

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We present a multi-dimensional numerical code to solve isothermal magnetohydrodynamic (IMHD) equations for use in modeling astrophysical flows. First, we have built a one-dimensional code which is based on an explicit finite-difference…

Astrophysics · Physics 2009-10-31 Jongsoo Kim , Dongsu Ryu , T. W. Jones , S. S. Hong

We focus here on a class of fourth-order parabolic equations that can be written as a system of second-order equations by introducing an auxiliary variable. We design a novel second-order fully discrete mixed finite element method to…

Numerical Analysis · Mathematics 2020-08-28 Sana Keita , Abdelaziz Beljadid , Yves Bourgault

The goal of the present paper is to understand the impact of numerical schemes for the reconstruction of data at cell faces in finite-volume methods, and to assess their interaction with the quadrature rule used to compute the average over…

Numerical Analysis · Mathematics 2021-06-15 Emmanuel Motheau , John Wakefield

This paper is concerned with mixed finite element method (FEM) for solving the two-dimensional, nonlinear fourth-order active fluid equations. By introducing an auxiliary variable $w=-\Delta u$, the original fourth problem is transformed…

Numerical Analysis · Mathematics 2025-07-30 Nan Zheng , Xu Guo , Wenlong Pei , Wenju Zhao

This paper proposes a new hybrid high-order discretization for the biharmonic problem and the corresponding eigenvalue problem. The discrete ansatz space includes degrees of freedom in $n-2$ dimensional submanifolds (e.g., nodal values in…

Numerical Analysis · Mathematics 2026-04-06 Yizhou Liang , Ngoc Tien Tran

The magnetohydrodynamics (MHD) equations are continuum models used in the study of a wide range of plasma physics systems, including the evolution of complex plasma dynamics in tokamak disruptions. However, efficient numerical solution…

Computational Physics · Physics 2022-02-09 Qi Tang , Luis Chacon , Tzanio V. Kolev , John N. Shadid , Xian-Zhu Tang

In tomographic reconstruction, the goal is to reconstruct an unknown object from a collection of line integrals. Given a complete sampling of such line integrals for various angles and directions, explicit inverse formulas exist to…

Numerical Analysis · Mathematics 2018-01-18 Tristan van Leeuwen , Simon Maretzke , K. Joost Batenburg

In the past decades, the finite difference methods for space fractional operators develop rapidly; to the best of our knowledge, all the existing finite difference schemes, including the first and high order ones, just work on uniform…

Numerical Analysis · Mathematics 2016-04-04 Lijing Zhao , Weihua Deng

We present an algorithm for simulating the equations of ideal magnetohydrodynamics and other systems of differential equations on an unstructured set of points represented by sample particles. Local, third-order, least-squares, polynomial…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Jason L. Maron , Colin P. McNally , Mordecai-Mark Mac Low

In the present chapter we focus on the fundamentals of non-grid-conforming numerical approaches to simulating particulate flows, implementation issues and grid convergence vs. available reference data. The main idea is to avoid adapting the…

Fluid Dynamics · Physics 2024-12-11 Markus Uhlmann , Jos Derksen , Anthony Wachs , Lian-Ping Wang , Manuel Moriche

We systematically validate the static local mesh refinement capabilities of a recently proposed IMEX-DG scheme implemented in the framework of the deal.II library. Non-conforming meshes are employed in atmospheric flow simulations to…

Atmospheric and Oceanic Physics · Physics 2025-08-27 Giuseppe Orlando , Tommaso Benacchio , Luca Bonaventura

We study a second order BDF (Backward Differentiation Formula) scheme for the numerical approximation of parabolic HJB (Hamilton-Jacobi-Bellman) equations. The scheme under consideration is implicit, non-monotone, and second order accurate…

Numerical Analysis · Mathematics 2018-02-21 Olivier Bokanowski , Athena Picarelli , Christoph Reisinger

We develop and analyze a highly efficient, second-order time-marching scheme for infinite-dimensional nonlinear geophysical fluid models, designed to accurately approximate invariant measures-that is, the stationary statistical properties…

Numerical Analysis · Mathematics 2025-10-08 Daozhi Han , Xiaoming Wang

Second order accurate Cartesian grid methods have been well developed for interface problems in the literature. However, it is challenging to develop third or higher order accurate methods for problems with curved interfaces and internal…

Numerical Analysis · Mathematics 2022-06-14 Zhilin Li , Kejia Pan , Juan Ruiz

Solving compressible flows containing both smooth and discontinuous flow structures remains a significant challenge for finite volume methods. Godunov-type finite volume methods are commonly used for numerical simulations of compressible…

Fluid Dynamics · Physics 2025-02-07 Minsheng Huang , Lidong Cheng , Wenjun Ying , Xi Deng , Feng Xiao

This dissertation is devoted to provide advanced nonconvex nonsmooth variational models of (Magnetic Resonance Image) MRI reconstruction, efficient learnable image reconstruction algorithms and parameter training algorithms that improve the…

Optimization and Control · Mathematics 2023-03-06 Wanyu Bian

Diffusion models (DMs) have demonstrated remarkable success in real-world image super-resolution (SR), yet their reliance on time-consuming multi-step sampling largely hinders their practical applications. While recent efforts have…

Computer Vision and Pattern Recognition · Computer Science 2026-05-13 Jiaqi Xu , Wenbo Li , Haoze Sun , Fan Li , Zhixin Wang , Long Peng , Jingjing Ren , Haoran Yang , Xiaowei Hu , Renjing Pei , Pheng-Ann Heng

In this paper we provide a detailed convergence analysis for an unconditionally energy stable, second-order accurate convex splitting scheme for the Modified Phase Field Crystal equation, a generalized damped wave equation for which the…

Numerical Analysis · Mathematics 2012-08-08 Arvind Baskaran , John Lowengrub , Cheng Wang , Steve Wise

It has now become customary in the field of numerical relativity to couple high order finite difference schemes to mesh refinement algorithms. To this end, different modifications to the standard Berger-Oliger adaptive mesh refinement…

General Relativity and Quantum Cosmology · Physics 2015-04-29 Bishop Mongwane

We describe a numerical method to solve the magnetohydrodynamic (MHD) equations. The fluid variables are updated along each direction using the flux conservative, 2nd order, total variation diminishing (TVD), upwind scheme of Jin and Xin.…

Astrophysics · Physics 2015-06-24 Ue-Li Pen , Phil Arras , ShingKwong Wong