activity
20182026
collaborators

5 papers

math.NA2026

Numerical analysis for the Stokes problem with non-homogeneous Dirichlet boundary condition

Thomas Apel, Katharina Lorenz, Johannes Pfefferer

The Stokes problem with non-homogeneous Dirichlet boundary condition is solved numerically using conforming discretizations and an approximation of the boundary datum in the corres…

math.OC2026

Dirichlet control problems with energy regularization governed by non-coercive elliptic equations

Thomas Apel, Mariano Mateos, Arnd Rösch

The present study investigates a linear-quadratic Dirichlet control problem governed by a non-coercive elliptic equation posed on a possibly non-convex polygonal domain. Tikhonov r…

math.NA2025

Weak and very weak solutions of the Laplace equation and the Stokes system with prescribed regularity

Thomas Apel, Katharina Lorenz, Serge Nicaise

To verify theoretical results it is sometimes important to use a numerical example where the solution has a particular regularity. The paper describes one approach to construct suc…

math.OC2024

Non-coercive Neumann boundary control problems

Thomas Apel, Mariano Mateos, Arnd Rösch

The article examines a linear-quadratic Neumann control problem that is governed by a non-coercive elliptic equation. Due to the non-self-adjoint nature of the linear control-to-st…

math.NA2018

-error estimates for Neumann boundary value problems on graded meshes

Thomas Apel, Johannes Pfefferer, Sergejs Rogovs +1

This paper deals with a priori pointwise error estimates for the finite element solution of boundary value problems with Neumann boundary conditions in polygonal domains. Due to th…