2 papers
math.FA2025
Sharp angle estimates for second order divergence operators
Hannes Meinlschmidt, Joachim Rehberg
This article is about the (minimal) sector containing the numerical range of the principal part of a linear second-order elliptic differential operator defined by a form on closed…
math.AP2025
Optimal Sobolev Regularity for Second Order Divergence Elliptic Operators on Domains with Buried Boundary Parts
Joachim Rehberg, Elmar Schrohe
We study the regularity of solutions of elliptic second order boundary value problems on a bounded domain in . The coefficients are not necessarily continuous and…