Reflection principles for functions of Neumann and Dirichlet Laplacians on open reflection invariant subsets of $\mathbb R^{d}$
Jacek Małecki, Krzysztof Stempak · Studia Mathematica · 2019
For an open subset $\Omega $ of $\mathbb R^d$, symmetric with respect to a hyperplane and with positive part $\Omega _+$, we consider the Neumann/Dirichlet Laplacians $-\Delta _{N/D,\Omega }$ and $-\Delta _{N/D,\Omega _+}$. Given a Borel function $\Phi $