paper

A Fatou theorem for -harmonic functions

arXiv:1407.0679

Abstract

In this paper we study a class of functions that appear naturally in some equidistribution problems and that we call -harmonic. These are functions of the universal cover of a closed and negatively curved which possess an integral representation analogous to the Poisson representation of harmonic functions, where the role of the Poisson kernel is played by a Hölder continuous kernel. More precisely we prove a theorem à la Fatou about the nontangential convergence of quotients of such functions, from which we deduce some basic properties such as the uniqueness of the -harmonic function on a compact manifold and of the integral representation of -harmonic functions.

arXiv comment26 pages, final version, to appear in Mathematische Zeitschrift