Title : The poset of elementary abelian subgroups of rank at least 2
Authors : Serge Bouc and Jacques Thévenaz

Abstract : Let p be a prime number, and P be a finite p-group. We prove 
that the poset of elementary abelian subgroups of rank at least 2 of P 
has the homotopy type of a wedge of spheres (of possibly different 
dimensions).

Status : published in "Guido's book of conjectures", Monographie N°40 de
l'Enseignement Mathématique - Genève (2008)