English

Free coarse groups

General Topology 2018-03-29 v1

Abstract

A coarse group is a group endowed with a coarse structure so that the group multiplication and inversion are coarse mappings. Let (X,E)(X, \mathcal{E}) be a coarse space and let M\mathfrak{M} be a variety of groups different from the variety of singletons. We prove that there is a coarse group FM(X,E)MF_{\mathfrak{M}} (X, \mathcal{E})\in \mathfrak{M} such that (X,E)(X, \mathcal{E}) is a subspace of FM(X,E)F_{\mathfrak{M}} (X, \mathcal{E}), XX generates FM(X,E)F_{\mathfrak{M}} (X, \mathcal{E}) and every coarse mapping (X,E)(G,E)(X, \mathcal{E}) \longrightarrow (G, \mathcal{E}^{\prime}) where GMG\in\mathfrak{M}, (G,E)(G, \mathcal{E}^{\prime}) is a coarse group, can be extended to coarse homomorphism FM(X,E)(G,E)F_{\mathfrak{M}} (X, \mathcal{E})\longrightarrow (G, \mathcal{E}^{\prime}) . If M\mathfrak{M} is the variety of all groups, the groups FM(X,E)F_{\mathfrak{M}} (X, \mathcal{E}) are asymptotic counterparts of Markov free topological groups over Tikhonov spaces.

Keywords

Cite

@article{arxiv.1803.10504,
  title  = {Free coarse groups},
  author = {Igor Protasov and Ksenia Protasova},
  journal= {arXiv preprint arXiv:1803.10504},
  year   = {2018}
}

Comments

Coarse space, coarse group, variety, free coarse group, Markov free topological group

R2 v1 2026-06-23T01:07:29.867Z