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Intrusive Uncertainty Quantification methods such as stochastic Galerkin are gaining popularity, whereas the classical stochastic Galerkin approach is not ensured to preserve hyperbolicity of the underlying hyperbolic system. We apply a…

Numerical Analysis · Mathematics 2019-12-20 Jakob Dürrwächter , Thomas Kuhn , Fabian Meyer , Louisa Schlachter , Florian Schneider

We study here the evolution of a massless scalar field in a spacetime, developing from a regular initial spacelike surface. The Einstein equations and regularity and boundary conditions governing the same are specified. Both homogeneous and…

General Relativity and Quantum Cosmology · Physics 2009-12-13 Swastik Bhattacharya , Rituparno Goswami , Pankaj S. Joshi

A deterministic method is proposed for solving the Boltzmann equation. The method employs a Galerkin discretization of the velocity space and adopts, as trial and test functions, the collocation basis functions based on weights and roots of…

Computational Physics · Physics 2013-11-19 Gian Pietro Ghiroldi , Livio Gibelli

In this paper we discuss the local discontinuous Galerkin methods coupled with two specific explicit-implicit-null time discretizations for solving one-dimensional nonlinear diffusion problems $U_t=(a(U)U_x)_x$. The basic idea is to add and…

Numerical Analysis · Mathematics 2019-03-29 Haijin Wang , Qiang Zhang , Shiping Wang , Chi-Wang Shu

We study gravitational collapse for the Starobinsky $R^2$ model, a particular example of an $f(r)$ theory, in a spherically symmetric spacetime. We add a massless scalar field as matter content to the spacetime. We work in the Einstein…

General Relativity and Quantum Cosmology · Physics 2023-01-02 Yolbeiker Rodríguez Baez

We present a new class of high-order accurate numerical algorithms for solving the equations of general-relativistic ideal magnetohydrodynamics in curved spacetimes. In this paper we assume the background spacetime to be given and static,…

Computational Physics · Physics 2018-05-28 Francesco Fambri , Michael Dumbser , Sven Köppel , Luciano Rezzolla , Olindo Zanotti

An efficient time-stepping algorithm is proposed based on operator-splitting and the space-time discontinuous Galerkin finite element method for problems in the non-classical theory of thermoelasticity. The non-classical theory incorporates…

Numerical Analysis · Mathematics 2015-05-05 Mebratu F. Wakeni , B. D. Reddy , A. T. McBride

We develop a stochastic Galerkin method for a coupled Navier-Stokes-cloud system that models dynamics of warm clouds. Our goal is to explicitly describe the evolution of uncertainties that arise due to unknown input data, such as model…

Numerical Analysis · Mathematics 2022-04-20 A. Chertock , A. Kurganov , M. Lukáčová-Medviďová , P. Spichtinger , B. Wiebe

In this work, we present a new high order Discontinuous Galerkin time integration scheme for second-order (in time) differential systems that typically arise from the space discretization of the elastodynamics equation. By rewriting the…

Numerical Analysis · Mathematics 2021-12-06 Paola F. Antonietti , Ilario Mazzieri , Francesco Migliorini

We study the model of spherically symmetric and spatially homogeneous gravitational collapse of a minimally coupled scalar field. Our study focuses on obtaining the scalar field potential that leads to a final equilibrium state in the…

General Relativity and Quantum Cosmology · Physics 2023-08-08 Dipanjan Dey , Koushiki , Pankaj S. Joshi

A linearized numerical scheme is proposed to solve the nonlinear time fractional parabolic problems with time delay. The scheme is based on the standard Galerkin finite element method in the spatial direction, the fractional Crank-Nicolson…

Numerical Analysis · Mathematics 2021-09-10 Lili Li , Mianfu She , Yuanling Niu

We propose and rigorously analyse semi- and fully discrete discontinuous Galerkin methods for an initial and boundary value problem describing inertial viscoelasticity in terms of elastic and viscoelastic stress components, and with mixed…

Numerical Analysis · Mathematics 2023-06-27 Salim Meddahi , Ricardo Ruiz-Baier

Dynamical low-rank approximation (DLRA) is an emerging tool for reducing computational costs and provides memory savings when solving high-dimensional problems. In this work, we propose and analyze a semi-implicit dynamical low-rank…

Numerical Analysis · Mathematics 2023-08-14 Peimeng Yin , Eirik Endeve , Cory D. Hauck , Stefan R. Schnake

A numerical method based on the hybridizable discontinuous Galerkin method in space and backward Euler in time is formulated and analyzed for solving the miscible displacement problem. Under low regularity assumptions, convergence is…

Numerical Analysis · Mathematics 2025-05-19 Keegan L. A. Kirk , Beatrice Riviere

In this work, approximate solutions to the nonlinear Klein-Gordon equation are constructed by means of the Galerkin method. Specifically, it is shown how the dynamics of a real scalar field in $1+1$ dimensions subjected to Dirichlet…

Mathematical Physics · Physics 2025-09-04 Annibal D. de Figueiredo Neto , Caio C. Holanda Ribeiro , Luana L. Silva Ribeiro

We explore a collapsing cosmology driven by a scalar field which is minimally coupled to gravity in a spatially at and spherically symmetric, isotropic and homogeneous space-time, with a variable timescale that avoids the final singularity.…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Jaime M. Hernandez , Mauricio Bellini , Claudia Moreno

This paper proposes and analyzes a fully discrete scheme that discretizes space with an ultra-weak local discontinuous Galerkin scheme and time with the Crank--Nicolson method for the nonlinear biharmonic Schr\"odinger equation. We first…

Numerical Analysis · Mathematics 2022-04-15 Lu Zhang

A particular class of space-time, with a tachyon field, \phi, and a barotropic fluid constituting the matter content, is considered herein as a model for gravitational collapse. For simplicity, the tachyon potential is assumed to be of…

General Relativity and Quantum Cosmology · Physics 2013-01-23 Yaser Tavakoli , João Marto , Amir Hadi Ziaie , Paulo Vargas Moniz

Kinetic schemes for compressible flow of gases are constructed by exploiting the connection between Boltzmann equation and the Navier-Stokes equations. This connection allows us to construct a flux splitting for the Navier-Stokes equations…

Numerical Analysis · Computer Science 2015-06-11 Praveen Chandrashekar

The discontinuous Galerkin (DG) method is an established method for computing approximate solutions of partial differential equations in many applications. Unlike continuous finite elements, in DG methods, numerical fluxes are used to…

Numerical Analysis · Mathematics 2019-12-02 Kenneth Duru , Leonhard Rannabauer , Alice-Agnes Gabriel , Heiner Igel