Finite groups of arbitrary deficiency
arXiv:1705.02040 · doi:10.1112/blms.12114
Abstract
The deficiency of a group is the maximum over all presentations for that group of the number of generators minus the number of relators. Every finite group has non-positive deficiency. We show that every non-positive integer is the deficiency of a finite group -- in fact, of a finite -group for every prime . This completes Kotschick's classification of the integers which are deficiencies of fundamental groups of compact Kaehler manifolds.
7 pages, 1 figure; v2 minor changes, to appear in the Bulletin of the London Mathematical Society