Cauchy universality and random billiards

Abstract

Motion in bounded domains represents a paradigm in several settings: from billiard dynamics, to random walks in a finite lattice, with applications to relevant physical, ecological and biological problems. A remarkable universal property, involving the average of return times to the boundary, has been theoretically proposed, and experimentally verified in quite different contexts. We discuss here mechanisms that lead to violations of universality, induced by boundary effects. We suggest that our analysis should be relevant where non homogeneity appears in the stationary probability distribution in bounded domain.