English

Representing fine shape of local compacta by homotopy classes of ordinary maps

General Topology 2025-10-16 v1 Algebraic Topology Geometric Topology Metric Geometry

Abstract

Fine shape, as defined by Melikhov, is an extension of the strong shape category of compacta (compact metrizable topological spaces) to all metrizable spaces, notable for being compatible with both \v{C}ech cohomology and Steenrod-Sitnikov homology. In this work we study fine shape of local compacta (locally compact separable metrizable spaces), and construct, for every local compactum XX, a space X|X| unique up to a homotopy equivalence and such that fine shape classes from any locally compact metrizable space YY to XX bijectively correspond to homotopy classes of ordinary maps from YY to X|X|. This correspondence is (contravariatly) functorial in YY, thus giving a representation of YY-dependent contravariant functor for a fixed XX; the universal class corresponding to the identity map of XX is the homotopy class of a specific embedding of XX into X|X| that is a fine shape equivalence.

Keywords

Cite

@article{arxiv.2510.12808,
  title  = {Representing fine shape of local compacta by homotopy classes of ordinary maps},
  author = {Vladislav Zemlyanoy},
  journal= {arXiv preprint arXiv:2510.12808},
  year   = {2025}
}

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17 pages