Abstract

A virtual Schottky group is a Kleinian group K containing a Schottky group G as a finite index normal subgroup. These groups correspond to those groups of automorphisms of closed Riemann surfaces which can be realized at the level of their lowest uniformizations. In this paper, we provide a geometrical structural decomposition of K. When K/G is an abelian group, an explicit free product decomposition in terms of Klein-Maskit's combination theorems is provided.