Towards a Stallings-type theorem for finite groups

Johannes Carmesin, George Kontogeorgiou, Jan Kurkofka, Will J. Turner

Published 2024-03-12Version 1

A recent development in graph theory is to study local separators, vertex sets that need not separate graphs globally but just locally. We use this idea to conjecture an extension of Stallings' theorem to finite nilpotent groups. We provide an example demonstrating that the assumption of nilpotency is necessary, and prove a stronger form of this conjecture for low connectivities, as follows. A finite nilpotent group that has a Cayley graph with a local separator of size at most two is cyclic, dihedral or a direct product of a cyclic group with the group of order two.