Generalized homotopy excision theorems modulo a Serre class of nilpotent groups

Abstract

The main results are stated in the context of Serre classes of nilpotent groups. Our proof of the Blakers-Massey theorem appears to be new, and applies moreover to any map of nilpotent spaces which induces an epimorphism of fundamental groups (cf. [18, Corollary 6, p. 487]). We close with a very general Freudenthal Suspension Theorem.