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In this article, we study the semi discrete and fully discrete formulations for a Kirchhoff type quasilinear integro-differential equation involving time-fractional derivative of order $\alpha \in (0,1) $. For the semi discrete formulation…

Numerical Analysis · Mathematics 2023-05-08 Lalit Kumar , Sivaji Ganesh Sista , Konijeti Sreenadh

The numerical approximation of high-frequency wave propagation in inhomogeneous media is a challenging problem. In particular, computing high-frequency solutions by direct simulations requires several points per wavelength for stability and…

Numerical Analysis · Mathematics 2017-09-13 Eric T. Chung , Chi Yeung Lam , Jianliang Qian

This paper develops an analogue (or counterpart) to discontinuous Galerkin (DG) methods for approximating a general class of calculus of variations problems. The proposed method, called the discontinuous Ritz (DR) method, constructs a…

Numerical Analysis · Mathematics 2018-01-19 Xiaobing Feng , Stefan Schnake

In this work, we investigate the propagation of electromagnetic waves in the Cole-Cole dispersive medium by using the discontinuous Galerkin (DG) method to solve the coupled time-domain Maxwell's equations and polarization equation. We…

Numerical Analysis · Mathematics 2022-08-25 Jiangming Xie , Maojun Li , Miao-Jung Yvonne Ou

We present a new line-based discontinuous Galerkin (DG) discretization scheme for first- and second-order systems of partial differential equations. The scheme is based on fully unstructured meshes of quadrilateral or hexahedral elements,…

Numerical Analysis · Mathematics 2015-06-04 Per-Olof Persson

We present an efficient nodal discontinuous Galerkin method for approximating nearly incompressible flows using the Boltzmann equations. The equations are discretized with Hermite polynomials in velocity space yielding a first order…

Numerical Analysis · Mathematics 2019-05-22 A. Karakus , N. Chalmers , J. S. Hesthaven , T. Warburton

Discontinuous Galerkin (DG) methods are widely adopted to discretize the radiation transport equation (RTE) with diffusive scalings. One of the most important advantages of the DG methods for RTE is their asymptotic preserving (AP)…

Numerical Analysis · Mathematics 2024-04-17 Cory D. Hauck , Qiwei Sheng , Yulong Xing

We propose a new discretization method for the Stokes equations. The method is an improved version of the method recently presented in [C. Lehrenfeld, J. Sch\"oberl, Comp. Meth. Appl. Mech. Eng., 361 (2016)] which is based on an…

Numerical Analysis · Mathematics 2018-03-29 Philip L. Lederer , Christoph Lehrenfeld , Joachim Schöberl

We extend the nonconforming Trefftz virtual element method introduced in arXiv:1805.05634 to the case of the fluid-fluid interface problem, that is, a Helmholtz problem with piecewise constant wave number. With respect to the original…

Numerical Analysis · Mathematics 2018-11-06 L. Mascotto , A. Pichler

A coupling approach is presented to combine a wave-based method to the standard finite element method. This coupling methodology is presented here for the Helmholtz equation but it can be applied to a wide range of wave propagation…

Computational Physics · Physics 2018-01-16 Mathieu Gaborit , Olivier Dazel , Peter Göransson , Gwénaël Gabard

We present new stabilization terms for solving the linear transport equation on a cut cell mesh using the discontinuous Galerkin (DG) method in two dimensions with piecewise linear polynomials. The goal is to allow for explicit time…

Numerical Analysis · Mathematics 2019-06-14 Christian Engwer , Sandra May , Andreas Nüßing , Florian Streitbürger

This paper considers weak Galerkin finite element approximations for a quasistatic Maxwell viscoelastic model. The spatial discretization uses piecewise polynomials of degree $k \ (k\geq 1)$ for the stress approximation, degree $k+1$ for…

Numerical Analysis · Mathematics 2022-02-22 Jihong Xiao , Zimo Zhu , Xiaoping Xie

In this paper we present a numerical method for the Boltzmann equation. It is a spectral discretization in the velocity and a discontinuous Galerkin discretization in physical space. To obtain uniform approximation properties in the mach…

Numerical Analysis · Mathematics 2019-03-06 Gerhard Kitzler , Joachim Schöberl

We couple the L1 discretization for Caputo derivative in time with spectral Galerkin method in space to devise a scheme that solves quasilinear subdiffusion equations. Both the diffusivity and the source are allowed to be nonlinear…

Numerical Analysis · Mathematics 2022-11-30 Łukasz Płociniczak

A new hybridizable discontinuous Galerkin method, named the CHDG method, is proposed for solving time-harmonic scalar wave propagation problems. This method relies on a standard discontinuous Galerkin scheme with upwind numerical fluxes and…

Numerical Analysis · Mathematics 2023-09-11 A. Modave , T. Chaumont-Frelet

In this paper a finite difference/local discontinuous Galerkin method for the fractional diffusion-wave equation is presented and analyzed. We first propose a new finite difference method to approximate the time fractional derivatives, and…

Numerical Analysis · Mathematics 2015-07-29 Leilei Wei

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 develop a hybrid spatial discretization for the wave equation in second order form, based on high-order accurate finite difference methods and discontinuous Galerkin methods. The hybridization combines computational efficiency of finite…

Numerical Analysis · Mathematics 2022-10-26 Siyang Wang , Gunilla Kreiss

We revisit second-order-in-time space-time discretizations of the linear and semilinear wave equations by establishing precise equivalences with first-order-in-time formulations. Focusing on schemes using continuous piecewise-polynomial…

Numerical Analysis · Mathematics 2026-01-07 Matteo Ferrari , Ilaria Perugia , Enrico Zampa

We develop and analyze a new hybridizable discontinuous Galerkin (HDG) method for solving third-order Korteweg-de Vries type equations. The approximate solutions are defined by a discrete version of a characterization of the exact solution…

Numerical Analysis · Mathematics 2026-05-25 Bo Dong