Equivariant CW-Complexes and the Orbit Category

Abstract

We give a general framework for studying G-CW complexes via the orbit category. As an application we show that the symmetric group G=S_5 admits a finite G-CW complex X homotopy equivalent to a sphere, with cyclic isotropy subgroups.

48 pages. The results are unchanged, but revisions to the exposition have been made following a referee's report