Some invariant properties of quasi-M\"obius maps

Abstract

We investigate properties which remain invariant under the action of quasi-M\"obius maps of quasi-metric spaces. A metric space is called doubling with constant D if every ball of finite radius can be covered by at most D balls of half the radius. It is shown that the doubling property is an invariant property for (quasi-)M\"obius spaces. Additionally it is shown that the property of uniform disconnectedness is an invariant for (quasi-)M\"obius spaces as well.