Plurisubharmonic functions with discontinuous boundary behavior

TL;DR

This paper investigates the Dirichlet problem for the complex Monge-Ampère operator with discontinuous boundary data, establishing existence, uniqueness, and regularity results under conditions involving b-pluripolar sets and B-regular domains.

Contribution

It extends the understanding of boundary value problems for complex Monge-Ampère equations to cases with discontinuous data, relaxing previous continuity requirements.

Findings

Existence and uniqueness of solutions with discontinuous boundary data.

Optimal results in the unit disk for boundary functions with b-pluripolar discontinuities.

Uniqueness and continuity can hold even with boundary discontinuities on small measure sets.

Abstract

We study the Dirichlet problem for the complex Monge-Amp\`ere operator with bounded, discontinuous boundary data. If the set of discontinuities is b-pluripolar and the domain is B-regular, we are able to prove existence, uniqueness and some regularity estimates for a large class of complex Monge-Amp\`ere measures. This result is optimal in the unit disk, as boundary functions with b-pluripolar discontinuity then coincides with functions that are continuous almost everywhere. We also show that neither of these properties of the boundary function - being continuous almost everywhere or having discontinuities forming a b-pluripolar set - are necessary conditions in order to establish uniqueness and continuity of the solution in higher dimensions. In particular, there are situations where it is enough to prescribe the boundary behavior at a set of arbitrarily small Lebesgue measure.