Analytic capacity, rectifiability, and the Cauchy integral

Abstract

A compact set E ⊂ ℂ is said to be removable for bounded analytic functions if for any open set Ω containing E, every bounded function analytic on Ω \ E has an analytic extension to Ω. Analytic capacity is a notion that, in a sense, measures the size of a set as a non removable singularity. In particular, a compact set is removable if and only if its analytic capacity vanishes. The so-called Painlevé problem consists in characterizing removable sets in geometric terms. Recently many results in connection with this very old and challenging problem have been obtained. Moreover, it has also been proved that analytic capacity is semiadditive. We review these results and other related questions dealing with rectifiability, the Cauchy transform, and the Riesz transforms.