English

Constructing a coarse space with a given Higson or binary corona

General Topology 2021-11-01 v3 Metric Geometry

Abstract

For any compact Hausdorff space KK we construct a canonical finitary coarse structure EX,K\mathcal E_{X,K} on the set XX of isolated points of KK. This construction has two properties: \bullet If a finitary coarse space (X,E)(X,\mathcal E) is metrizable, then its coarse structure E\mathcal E coincides with the coarse structure EX,Xˉ\mathcal E_{X,\bar X} generated by the Higson compactification Xˉ\bar X of XX; \bullet A compact Hausdorff space KK coincides with the Higson compactification of the coarse space (X,EX,K)(X,\mathcal E_{X,K}) if the set XX is dense in KK and the space KK is Frechet-Urysohn. This implies that a compact Hausdorff space KK is homeomorphic to the Higson corona of some finitary coarse space if one of the following conditions holds: (i) KK is perfectly normal; (ii) KK has weight w(K)ω1w(K)\le\omega_1 and character χ(K)<p\chi(K)<\mathfrak p. Under CH every (zero-dimensional) compact Hausdorff space of weight ω1\le\omega_1 is homeomorphic to the Higson (resp. binary) corona of some cellular finitary coarse space.

Keywords

Cite

@article{arxiv.2002.00409,
  title  = {Constructing a coarse space with a given Higson or binary corona},
  author = {Taras Banakh and Igor Protasov},
  journal= {arXiv preprint arXiv:2002.00409},
  year   = {2021}
}

Comments

20 pages

R2 v1 2026-06-23T13:28:12.545Z