The EMS Publishing House is now EMS Press and has its new home at

Please find all EMS Press journals and articles on the new platform.

Commentarii Mathematici Helvetici

Full-Text PDF (454 KB) | Metadata | Table of Contents | CMH summary
Volume 88, Issue 2, 2013, pp. 369–425
DOI: 10.4171/CMH/289

Published online: 2013-04-24

Equivariant CW-complexes and the orbit category

Ian Hambleton[1], Semra Pamuk[2] and Ergün Yalçın[3]

(1) McMaster University, Hamilton, Canada
(2) Middle East Technical University, Ankara, Turkey
(3) Bilkent University, Bilkent, Ankara, Turkey

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.

Keywords: Finite group actions on spheres, orbit category, chain complexes

Hambleton Ian, Pamuk Semra, Yalçın Ergün: Equivariant CW-complexes and the orbit category. Comment. Math. Helv. 88 (2013), 369-425. doi: 10.4171/CMH/289