Decomposition of polyharmonic functions with respect to the complex Dunkl Laplacian.
Let be a closed polar subset of a domain in . We give a complete description of the pluripolar hull of the graph of a holomorphic function defined on . To achieve this, we prove for pluriharmonic measure certain semi-continuity properties and a localization principle.
Let be the Riesz capacity of order α, 0 < α < n, in ℝⁿ. We consider the Riesz capacity density for a Borel set E ⊂ ℝⁿ, where B(x,r) stands for the open ball with center at x and radius r. In case 0 < α ≤ 2, we show that is either 0 or 1; the first case occurs if and only if is identically zero for all r > 0. Moreover, it is shown that the densities with respect to more general open sets enjoy the same dichotomy. A decay estimate for α-capacitary potentials is also obtained.
Let be a sub-laplacian on a stratified Lie group . In this paper we study the Dirichlet problem for with -boundary data, on domains which are contractible with respect to the natural dilations of . One of the main difficulties we face is the presence of non-regular boundary points for the usual Dirichlet problem for . A potential theory approach is followed. The main results are applied to study a suitable notion of Hardy spaces.