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In this article we present an a posteriori error estimator for the spatial-stochastic error of a Galerkin-type discretisation of an initial value problem for a random hyperbolic conservation law. For the stochastic discretisation we use the…

Numerical Analysis · Mathematics 2019-02-22 Jan Giesselmann , Fabian Meyer , Christian Rohde

In this paper we investigate the numerical approximation of the fractional diffusion, advection, reaction equation on a bounded interval. Recently the explicit form of the solution to this equation was obtained. Using the explicit form of…

Numerical Analysis · Mathematics 2020-02-07 Xiangcheng Zheng , V. J. Ervin , Hong Wang

Higher resolution telescopes as well as 3D numerical simulations will require the development of detailed 3D radiative transfer calculations. Building upon our previous work we extend our method to include both continuum and line transfer.…

Astrophysics · Physics 2009-11-13 E. Baron , Peter H. Hauschildt

Background: The numerical solution of few-body scattering problems with realistic interactions is a difficult problem that normally must be solved on powerful supercomputers, taking a lot of computer time. This strongly limits the…

Nuclear Theory · Physics 2014-07-09 V. N. Pomerantsev , V. I. Kukulin , O. A. Rubtsova

This paper focuses on the adaptive discontinuous Galerkin (DG) methods for the tempered fractional (convection) diffusion equations. The DG schemes with interior penalty for the diffusion term and numerical flux for the convection term are…

Numerical Analysis · Mathematics 2020-06-16 Xudong Wang , Weihua Deng

We perform a posteriori error analysis in the supremum norm for the quadratic discontinuous Galerkin method for the elliptic obstacle problem. We define two discrete sets (motivated by Gaddam, Gudi and Kamana [1]), one set having integral…

Numerical Analysis · Mathematics 2022-09-13 Rohit Khandelwal , Kamana Porwal , Ritesh Singla

We present multi-adaptive versions of the standard continuous and discontinuous Galerkin methods for ODEs. Taking adaptivity one step further, we allow for individual time-steps, order and quadrature, so that in particular each individual…

Numerical Analysis · Mathematics 2012-05-15 Anders Logg

Least-squares Petrov--Galerkin (LSPG) model-reduction techniques such as the Gauss--Newton with Approximated Tensors (GNAT) method have shown promise, as they have generated stable, accurate solutions for large-scale turbulent, compressible…

Numerical Analysis · Computer Science 2016-08-18 Kevin Carlberg , Matthew Barone , Harbir Antil

In this article we investigate a finite element formulation of strongly monotone quasi-linear elliptic PDEs in the context of fixed-point iterations. As opposed to Newton's method, which requires information from the previous iteration in…

Numerical Analysis · Mathematics 2015-07-01 Scott Congreve , Thomas P. Wihler

This work presents algorithms for the efficient implementation of discontinuous Galerkin methods with explicit time stepping for acoustic wave propagation on unstructured meshes of quadrilaterals or hexahedra. A crucial step towards…

Numerical Analysis · Computer Science 2019-03-06 Svenja Schoeder , Katharina Kormann , Wolfgang Wall , Martin Kronbichler

We define an a posteriori verification procedure that enables to control and certify PGD-based model reduction techniques applied to parametrized linear elliptic or parabolic problems. Using the concept of constitutive relation error, it…

Numerical Analysis · Mathematics 2018-06-22 Ludovic Chamoin , Florent Pled , Pierre-Eric Allier , Pierre Ladevèze

We consider the Galerkin boundary element method (BEM) for weakly-singular integral equations of the first-kind in 2D. We analyze some residual-type a posteriori error estimator which provides a lower as well as an upper bound for the…

Numerical Analysis · Mathematics 2015-04-24 Michael Feischl , Gregor Gantner , Dirk Praetorius

We analyze the inverse problem to reconstruct the shape of a three dimensional homogeneous dielectric obstacle from the knowledge of noisy far field data. The forward problem is solved by a system of second kind boundary integral equations.…

Numerical Analysis · Mathematics 2020-06-22 Thorsten Hohage , Frédérique Le Louër

In this article we consider one-dimensional random systems of hyperbolic conservation laws. We first establish existence and uniqueness of random entropy admissible solutions for initial value problems of conservation laws which involve…

Numerical Analysis · Mathematics 2020-03-16 Jan Giesselmann , Fabian Meyer , Christian Rohde

High-dimensional transport equations frequently occur in science and engineering. Computing their numerical solution, however, is challenging due to its high dimensionality. In this work we develop an algorithm to efficiently solve the…

Numerical Analysis · Mathematics 2023-08-02 Andreas Zeiser

This thesis explores the application of Plane Wave Discontinuous Galerkin (PWDG) methods for the numerical simulation of electromagnetic scattering by periodic structures. Periodic structures play a pivotal role in various engineering and…

Numerical Analysis · Mathematics 2023-12-20 Armando Maria Monforte

We present an anisotropic $hp-$mesh adaptation strategy using a continuous mesh model for discontinuous Petrov-Galerkin (DPG) finite element schemes with optimal test functions, extending our previous work on $h-$adaptation. The proposed…

Computational Engineering, Finance, and Science · Computer Science 2022-11-22 Ankit Chakraborty , Georg May

In this study, we consider a class of non-autonomous time-fractional partial advection-diffusion-reaction (TF-ADR) equations with Caputo type fractional derivative. To obtain the numerical solution of the model problem, we apply the…

Numerical Analysis · Mathematics 2023-08-08 Sandip Maji , Srinivasan Natesan

In this paper, we use an implicit two-derivative deferred correction time discretization approach and combine it with a spatial discretization of the discontinuous Galerkin spectral element method to solve (non-)linear PDEs. The resulting…

Numerical Analysis · Mathematics 2022-07-13 Jonas Zeifang , Jochen Schuetz

This paper presents an a-posteriori goal-oriented error analysis for a numerical approximation of the steady Boltzmann equation based on a moment-system approximation in velocity dependence and a discontinuous Galerkin finite-element (DGFE)…

Numerical Analysis · Mathematics 2017-10-11 M. R. A. Abdelmalik , E. H. van Brummelen