MINRES for second-order PDEs with singular data

T Führer, N Heuer, M Karkulik - SIAM Journal on Numerical Analysis, 2022 - SIAM
Minimum residual methods such as the least-squares finite element method (FEM) or the
discontinuous Petrov--Galerkin (DPG) method with optimal test functions usually exclude …

Minimal residual methods in negative or fractional Sobolev norms

H Monsuur, R Stevenson, J Storn - Mathematics of Computation, 2024 - ams.org
For numerical approximation the reformulation of a PDE as a residual minimisation problem
has the advantages that the resulting linear system is symmetric positive definite, and that …

[引用][C] Local L2-bounded commuting projections in FEEC

D Arnold, J Guzmán - ESAIM: Mathematical Modelling and …, 2021 - esaim-m2an.org
Local L2-bounded commuting projections in FEEC Page 1 ESAIM: M2AN 55 (2021) 2169–2184
ESAIM: Mathematical Modelling and Numerical Analysis https://doi.org/10.1051/m2an/2021054 …

Frequency-explicit a posteriori error estimates for finite element discretizations of Maxwell's equations

T Chaumont-Frelet, P Vega - SIAM Journal on Numerical Analysis, 2022 - SIAM
We consider residual-based a posteriori error estimators for Galerkin discretizations of time-
harmonic Maxwell's equations. We focus on configurations where the frequency is high, or …

Multilevel decompositions and norms for negative order Sobolev spaces

T Führer - Mathematics of Computation, 2022 - ams.org
We consider multilevel decompositions of piecewise constants on simplicial meshes that are
stable in $ H^{-s} $ for $ s\in (0, 1) $. Proofs are given in the case of uniformly and locally …

On a Mixed FEM and a FOSLS with 𝐻−1 Loads

T Führer - Computational Methods in Applied Mathematics, 2024 - degruyter.com
We study variants of the mixed finite element method (mixed FEM) and the first-order system
least-squares finite element (FOSLS) for the Poisson problem where we replace the load by …

Constrained and unconstrained stable discrete minimizations for p-robust local reconstructions in vertex patches in the de Rham complex

T Chaumont-Frelet, M Vohralík - 2022 - inria.hal.science
We analyze constrained and unconstrained minimization problems on patches of tetrahedra
sharing a common vertex with discontinuous piecewise polynomial data of degree p. We …

Local finite element approximation of Sobolev differential forms

E Gawlik, MJ Holst, MW Licht - ESAIM: Mathematical Modelling …, 2021 - esaim-m2an.org
We address fundamental aspects in the approximation theory of vector-valued finite element
methods, using finite element exterior calculus as a unifying framework. We generalize the …

[HTML][HTML] A pollution-free ultra-weak FOSLS discretization of the Helmholtz equation

H Monsuur, R Stevenson - Computers & Mathematics with Applications, 2023 - Elsevier
We consider an ultra-weak first order system discretization of the Helmholtz equation. When
employing the optimal test norm, the 'ideal'method yields the best approximation to the pair …

Smoothed projections over manifolds in finite element exterior calculus

MW Licht - arXiv preprint arXiv:2310.14276, 2023 - arxiv.org
We develop commuting finite element projections over smooth Riemannian manifolds. This
extension of finite element exterior calculus establishes the stability and convergence of …