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In this paper we design discrete port-Hamiltonian systems systematically in two different ways, by applying discrete gradient methods and splitting methods respectively. The discrete port-Hamiltonian systems we get satisfy a discrete notion…

Numerical Analysis · Mathematics 2017-06-28 Elena Celledoni , Eirik Hoel Høiseth

In this paper, we propose a feasible algorithm to give an explicit basis of the space of regular differential forms on the nonsingular projective model of any given plane algebraic curve. The algorithm is demonstrated for concrete examples,…

Algebraic Geometry · Mathematics 2022-03-23 Momonari Kudo , Shushi Harashita

The numerical approximation of some Boussinesq systems in two spatial dimensions is here considered. The differential systems under study are proposed as asymptotic models for the propagation of waves along the interface of two layers of…

Numerical Analysis · Mathematics 2026-05-05 A. Durán

We present and analyse a new conforming space-time Galerkin discretisation of a semi-linear wave equation, based on a variational formulation derived from De Giorgi's elliptic regularisation viewpoint of the wave equation in second-order…

Numerical Analysis · Mathematics 2025-10-22 Lehel Banjai , Emmanuil H. Georgoulis , Brian Hennessy

In this work, we consider space-time goal-oriented a posteriori error estimation for parabolic problems. Temporal and spatial discretizations are based on Galerkin finite elements of continuous and discontinuous type. The main objectives…

Numerical Analysis · Mathematics 2024-02-06 Jan Philipp Thiele , Thomas Wick

In backward error analysis, an approximate solution to an equation is compared to the exact solution to a nearby modified equation. In numerical ordinary differential equations, the two agree up to any power of the step size. If the…

Numerical Analysis · Mathematics 2022-07-21 Robert I McLachlan , Christian Offen

The paper presents results for deriving closed-form analytic solutions of the non-relativistic linear perturbation equations, which govern the evolution of inhomogeneities in a homogeneous spatially flat multicomponent cosmological model.…

Astrophysics · Physics 2009-10-22 H. J. Haubold , A. M. Mathai

We introduce a very weak space-time variational formulation for the wave equation, prove its well-posedness (even in the case of minimal regularity) and optimal inf-sup stability. Then, we introduce a tensor product-style space-time…

Numerical Analysis · Mathematics 2021-07-27 Julian Henning , Davide Palitta , Valeria Simoncini , Karsten Urban

We have been calculated the ground state charge densities and energies of noble gas atoms through a single time dependent quantum fluid Schr$\ddot{o}$dinger equation. By using imaginary - time, the Schr$\ddot{o}$dinger equation has been…

Computational Physics · Physics 2018-10-03 D. Naranchimeg , L. Khenmedekh , G. Munkhsaikhan , N. Tsogbadrakh

We find initial data for numerical relativity simulations of inhomogeneous cosmologies. This involves treating an exceptional case of the general relativity constraint equations. We devise analytic and numerical methods to treat this…

General Relativity and Quantum Cosmology · Physics 2020-08-19 David Garfinkle , Lawrence Mead

Starting from space-discretisation of Maxwell's equations, various classical formulations are proposed for the simulation of electromagnetic fields. They differ in the phenomena considered as well as in the variables chosen for…

Numerical Analysis · Mathematics 2019-04-09 Idoia Cortes Garcia , Sebastian Schöps , Herbert De Gersem , Sascha Baumanns

In this paper we study a numerical implementation for the initial boundary value formulation for the generalized conformal field equations. We propose a formulation which is well suited for the study of the long-time behaviour of perturbed…

General Relativity and Quantum Cosmology · Physics 2017-10-18 Florian Beyer , Jörg Frauendiener , Chris Stevens , Ben Whale

In this article, an advanced differential quadrature (DQ) approach is proposed for the high-dimensional multi-term time-space-fractional partial differential equations (TSFPDEs) on convex domains. Firstly, a family of high-order difference…

Numerical Analysis · Mathematics 2021-01-28 Xiaogang Zhu , Yufeng Nie , Jungang Wang , Zhanbin Yuan

This paper is part of a program to combine a staggered time and staggered spatial discretization of continuum wave equations so that important properties of the continuum that are proved using vector calculus can be proven in an analogous…

Numerical Analysis · Mathematics 2020-10-13 Stanly Steinberg

We present a numerical method for approximating the solutions of degenerate parabolic equations with a formal gradient flow structure. The numerical method we propose preserves at the discrete level the formal gradient flow structure,…

Analysis of PDEs · Mathematics 2016-02-11 Clément Cancès , Cindy Guichard

Time-spectral solution of ordinary and partial differential equations is often regarded as an inefficient approach. The associated extension of the time domain, as compared to finite difference methods, is believed to result in…

Computational Physics · Physics 2017-04-14 Jan Scheffel , Kristoffer Lindvall

We present a general method which can be used for geometrical and physical interpretation of an arbitrary spacetime in four or any higher number of dimensions. It is based on the systematic analysis of relative motion of free test…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Jiri Podolsky , Robert Svarc

The paper investigates a non-intrusive parallel time integration with multigrid for space-fractional diffusion equations in two spatial dimensions. We firstly obtain a fully discrete scheme via using the linear finite element method to…

Numerical Analysis · Mathematics 2018-05-18 Xiaoqiang Yue , Shi Shu , Xiaowen Xu , Weiping Bu , Kejia Pan

We introduce a novel approach for detecting gravitational waves through their influence on the shape of resolved astronomical objects. This method, complementary to pulsar timing arrays and astrometric techniques, explores the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-22 Giorgio Mentasti , Carlo R. Contaldi

Harmonic slicing has in recent years become a standard way of prescribing the lapse function in numerical simulations of general relativity. However, as was first noticed by Alcubierre (1997), numerical solutions generated using this…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S. D. Hern