Computability of Følner sets
arXiv:1606.04293 · doi:10.1142/S0218196717500382
Abstract
We define the notion of computability of Følner sets for finitely generated amenable groups. We prove, by an explicit description, that the Kharlampovich group, a finitely presented solvable group with unsolvable word problem, has computable Følner sets. We also prove computability of Følner sets for a group that is extension of an amenable group with solvable word problem by a finitely generated group with computable Følner sets with subrecursive distortion function. Moreover we obtain some known and some new upper bounds for the Følner function in these particular extensions.
13 pages