Boundary Value Problems for harmonic functions on domains in Sierpinski gaskets

Original · EN

We study boundary value problems for harmonic functions on certain domains in the level-l Sierpinski gaskets SGₗ(l≥ 2) whose boundaries are Cantor sets. We give explicit analogues of the Poisson integral formula to recover harmonic functions from their boundary values. Three types of domains, the left half domain of SGₗ and the upper and lower domains generated by horizontal cuts of SGₗ are considered at present. We characterize harmonic functions of finite energy and obtain their energy estimates in terms of their boundary values. This paper settles several open problems raised in previous work.