Zugehörigkeit:
MPIM/Southampton
Datum:
Don, 18/06/2026 - 13:30 - 15:00
A classical theorem of M. Hall states that every finitely generated subgroup of a free group is a free factor of a finite index subgroup. Moreover, the works of Brunner--Burns and Dunwoody, imply that any finitely presented group satisfying this M. Hall's property must be virtually free, i.e., it must have a finite index free subgroup. However, many virtually free groups fail to have M. Hall's property. In the talk I will discuss the result that a weaker property (LR), defined by Long and Reid, does holds in all virtually free groups.