Generalized solutions to semilinear elliptic equations with measure data

Tomasz Klimsiak

Published 2023-10-11Version 1

We solve an open problem posed by H. Brezis, M. Marcus and A.C. Ponce in: Nonlinear elliptic equations with measures revisited. In: Mathematical Aspects of Nonlinear Dispersive Equations (J. Bourgain, C. Kenig, S. Klainerman, eds.), Annals of Mathematics Studies, 163 (2007). We prove that for any bounded Borel measure $\mu$ on a smooth bounded domain $D\subset\mathbb R^d$ and non-increasing (with respect to the second variable) non-positive continuous function $f$ on $D\times\mathbb R$ the sequence of solutions to the semi-linear equation (P): $-\Delta u=f(\cdot,u)+\rho_n\ast\mu$ ($\rho_n$ is a mollifier) that is subject to homogeneous Dirichlet condition, converges to the function that solves (P) with $\rho_n\ast\mu$ replaced by the reduced measure $\mu^*$ (metric projection onto the space of good measures). We also provide a corresponding version of this result without non-positivity assumption on $f$.