Relationship among various Vietoris-type and microsimplicial homology theories

Takuma Imamura

Address: Research Institute for Mathematical Sciences, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan


Abstract: In this paper, we clarify the relationship among the Vietoris-type homology theories and the microsimplicial homology theories, where the latter are nonstandard homology theories defined by M.C. McCord (for topological spaces), T. Korppi (for completely regular topological spaces) and the author (for uniform spaces). We show that McCord’s and our homology are isomorphic for all compact uniform spaces and that Korppi’s and our homology are isomorphic for all fine uniform spaces. Our homology shares many good properties with Korppi’s homology. As an example, we outline a proof of the continuity of our homology with respect to uniform resolutions. S. Garavaglia proved that McCord’s homology is isomorphic to Vietoris homology for all compact topological spaces. Inspired by this result, we prove that our homology is isomorphic to uniform Vietoris homology for all precompact uniform spaces and that Korppi’s homology is isomorphic to normal Vietoris homology for all pseudocompact completely regular topological spaces.

AMSclassification: primary 55N05; secondary 55N35, 54J05.

Keywords: McCord homology, Korppi homology, \mu -homology, Vietoris homology, nonstandard analysis.

DOI: 10.5817/AM2021-3-131