2019/06/11 by Gitik, Rita, Rips, Eliyahu
#20E05 #20E26 #22A05 #FOS: Mathematics #Group Theory (math.GR)
paper · doi:10.48550/arxiv.1906.07275
We present examples of closed subsets of a free group such that their product is not closed in the profinite topology. We discuss how to characterize a subset of a free group which is closed in the profinite topology and its product with any finitely generated subgroup of a free group is also closed in the profinite topology.