In this talk, the stationary limit of Lorentz-violating electrodynamics is discussed. As illustrated by some simple examples, the general solution includes unconven-tional mixing of electrostatic and magnetostatic effects. I discuss a high-sensitivity null-type measurement, exploiting Lorentz-violating electromagnetostatic effects, that could improve existing limits on parity-odd coefficients f...

A recently developed robust Algebraic Multigrid (AMG) method for the efficient solution of 3D nonlinear electrostatic and magnetostatic field problems will be presented. The method is directed to large matrix equations which arise from finite element (FE) discretization where AMG is used as a preconditioner in the Preconditioned Conjugate Gradient (PCG) method. Numerical results will demonstrat...

The conjecture that energy transport in sunspot penumbrae occurs through convection by an interchange of magnetic flux tubes is used in order to construct a magnetostatic model for a deep penumbra which is part of a global sunspot model. The model describes an overall mechanical equilibrium between the three stratifications: of the umbra, the penumbra, and of the solar convection zone, all of t...