2020/03/18 by Protasov, Igor
#FOS: Mathematics #General Topology (math.GN)
paper · doi:10.48550/arxiv.2003.12014
For a coarse space (X, E), X^\sharp denotes the set of all unbounded ultrafilters on X endowed with the parallelity relation: p||q if there exists E ∈ E such that E[P]∈ q for each P∈ p. If (X, E) is finitary then there exists a group G of permutations of X such that the coarse structure E has the base \\ (x,gx): x∈ X, g∈ F\: F∈ [G]^