On the size of boundary pluripolar sets
Mårten Nilsson
TL;DR
The paper analyzes the size and propagation of boundary pluripolar sets, which are the exceptional sets for the Dirichlet problem for the complex Monge-Ampère equation. It extends Stout's results on peak sets to boundary b-pluripolar $F_\sigma$ sets, shows that such sets with topological dimension exceeding $N-1$ must propagate into the interior, and proves that sufficiently small Hausdorff dimension implies b-pluripolarity and non-propagation under suitable boundary regularity. It also proves that Jensen measures and representing measures do not coincide on smooth, strictly pseudoconvex domains, extending Hedenmalm, by constructing measures that separate the two classes. Together, these results clarify the boundary singularity structure and lifting properties of pluripotential-theoretic hulls and provide tools for analyzing solvability of the Dirichlet problem in several complex variables.
Abstract
We prove a number of results related to the size and propagation of boundary pluripolar sets, the exceptional sets for the Dirichlet problem for the complex Monge--Ampère equation. We extend Stout's result that peak sets on strictly pseudoconvex domains $Ω\subset\mathbb{C}^N$ must have topological dimension less than $N$ to also encompass non-propagating boundary pluripolar $F_σ$ sets. In particular, boundary pluripolar sets must propagate into the interior if their topological dimension exceeds $N-1$. We also prove that sets of sufficiently small Hausdorff dimension must be boundary pluripolar and non-propagating, provided that the domain admits peak functions with sufficient boundary regularity. Lastly, we prove that the class of Jensen measures and the class of representing measures do not coincide on any smooth, strictly pseudoconvex domain. This extends a result of Hedenmalm.
