English
Related papers

Related papers: Convergence of Lagrange Finite Element Methods for…

200 papers

The convergence of the so-called quadratic method for computing eigenvalue enclosures of general self-adjoint operators is examined. Explicit asymptotic bounds for convergence to isolated eigenvalues are found. These bounds turn out to…

Numerical Analysis · Mathematics 2016-11-26 Lyonell Boulton , Aatef Hobiny

We introduce a new numerical method for solving time-harmonic Maxwell's equations via the modified weak Galerkin technique. The inter-element functions of the weak Galerkin finite elements are replaced by the average of the two…

Numerical Analysis · Mathematics 2023-08-08 Chunmei Wang , Xiu Ye , Shangyou Zhang

We prove that the superconvergence of $C^0$-$Q^k$ finite element method at the Gauss Lobatto quadrature points still holds if variable coefficients in an elliptic problem are replaced by their piecewise $Q^k$ Lagrange interpolant at the…

Numerical Analysis · Mathematics 2019-10-24 Hao Li , Xiangxiong Zhang

We propose and analyze a discontinuous least squares finite element method for solving the indefinite time-harmonic Maxwell equations. The scheme is based on the $L^2$ norm least squares functional with the weak imposition of the continuity…

Numerical Analysis · Mathematics 2020-07-15 Ruo Li , Qicheng Liu , Fanyi Yang

In this paper, we observe an interesting phenomenon for a hybridizable discontinuous Galerkin (HDG) method for eigenvalue problems. Specifically, using the same finite element method, we may achieve both upper and lower eigenvalue bounds…

Numerical Analysis · Mathematics 2024-10-01 Qigang Liang , Xuejun Xu , Liuyao Yuan

We study the effects of numerical quadrature rules on error convergence rates when solving Maxwell-type variational problems via the curl-conforming or edge finite element method. A complete {\em a priori} error analysis for the case of…

Numerical Analysis · Mathematics 2020-11-06 Rubén Aylwin , Carlos Jerez-Hanckes

Optimally convergent (with respect to the regularity) quadratic finite element method for two dimensional obstacle problem on simplicial meshes is studied in (Brezzi, Hager, Raviart, Numer. Math, 28:431--443, 1977). There was no analogue of…

Numerical Analysis · Mathematics 2016-11-10 Sharat Gaddam , Thirupathi Gudi

In this paper we establish a best approximation property of fully discrete Galerkin finite element solutions of second order parabolic problems on convex polygonal and polyhedral domains in the $L^\infty$ norm. The discretization method…

Numerical Analysis · Mathematics 2018-08-20 Dmitriy Leykekhman , Boris Vexler

In this paper, we examine the effectiveness of classic multiscale finite element method (MsFEM) (Hou and Wu, 1997; Hou et al., 1999) for mixed Dirichlet-Neumann, Robin and hemivariational inequality boundary problems. Constructing so-called…

Numerical Analysis · Mathematics 2020-02-06 Changqing Ye , Hao Dong , Junzhi Cui

A novel finite element method for the approximation of Maxwell's equations over hybrid two-dimensional grids is studied. The choice of appropriate basis functions and numerical quadrature leads to diagonal mass matrices which allow for…

Numerical Analysis · Mathematics 2022-09-22 Herbert Egger , Bogdan Radu

We present a new approach to compute selected eigenvalues and eigenvectors of the two-parameter eigenvalue problem. Our method requires computing generalized eigenvalue problems of the same size as the matrices of the initial two-parameter…

Numerical Analysis · Mathematics 2021-05-12 Henrik Eisenmann , Yuji Nakatsukasa

The Lagrange-mesh method is a very accurate procedure to compute eigenvalues and eigenfunctions of a two-body quantum equation. The method requires only the evaluation of the potential at some mesh points in the configuration space. It is…

Computational Physics · Physics 2011-09-21 Gwendolyn Lacroix , Claude Semay

Metamaterial homogenization theories usually start with crude approximations that are valid in certain limits in zero order, such as small frequencies, wave vectors and material fill fractions. In some cases they remain surprisingly robust…

Optics · Physics 2022-01-25 Antonio Günzler , Cedric Schumacher , Matthias Saba

This paper develops an enhanced finite element method for approximating a class of variational problems which exhibit the \textit{Lavrentiev gap phenomenon} in the sense that the minimum values of the energy functional have a nontrivial gap…

Numerical Analysis · Mathematics 2016-10-12 Xiaobing Feng , Stefan Schnake

For the quadratic Lagrange interpolation function, an algorithm is proposed to provide explicit and verified bound for the interpolation error constant that appears in the interpolation error estimation. The upper bound for the…

Numerical Analysis · Mathematics 2017-04-27 Xuefeng Liu , Chun'guang You

This study proposes a class of augmented subspace schemes for the weak Galerkin (WG) finite element method used to solve eigenvalue problems. The augmented subspace is built with the conforming linear finite element space defined on the…

Numerical Analysis · Mathematics 2024-01-09 Yue Feng , Zhijin Guan , Hehu Xie , Chenguang Zhou

In this paper, a new type of multi-level correction scheme is proposed for solving eigenvalue problems by finite element method. With this new scheme, the accuracy of eigenpair approximations can be improved after each correction step which…

Numerical Analysis · Mathematics 2011-07-04 Qun Lin , Hehu Xie

Maxwell's equations describe the evolution of electromagnetic fields, together with constraints on the divergence of the magnetic and electric flux densities. These constraints correspond to fundamental physical laws: the nonexistence of…

Numerical Analysis · Mathematics 2025-06-02 Yakov Berchenko-Kogan , Ari Stern

We derive low-order, inf-sup stable and divergence-free finite element approximations for the Stokes problem using Worsey-Farin splits in three dimensions and Powell-Sabin splits in two dimensions. The velocity space simply consists of…

Numerical Analysis · Mathematics 2022-02-02 Maurice Fabien , Johnny Guzman , Michael Neilan , Ahmed Zytoon

In this note we discuss the numerical solution of the eddy current approximation of the Maxwell equations using the simple Pragmatic Algebraic Model to include hysteresis effects. In addition to the more standard time-stepping approach we…

Numerical Analysis · Mathematics 2025-04-17 Mario Gobrial , Lukas Domenig , Michael Reichelt , Manfred Kaltenbacher , Olaf Steinbach