English

Between homeomorphism type and Tukey type

General Topology 2019-12-20 v2

Abstract

Call a compact space XX pin homogeneous if every two points a,ba,b are pin equivalent, meaning that there exists a compact space YY, a quotient map f ⁣:YXf\colon Y\to X, and a homeomorphism g ⁣:YYg\colon Y\to Y such that gf1{a}=f1{b}gf^{-1}\{a\}=f^{-1}\{b\}. We will prove a representation theorem for pin equivalence; transitivity of pin equivalence will be a corollary. Pin homogeneity is strictly weaker than homogeneity and pin equivalence is strictly stronger than Tukey equivalence. Just as with topological homogeneity, no infinite compact FF-space is pin homogeneous. On the other hand, X×2χ(X)X\times 2^{\chi(X)} is pin homogeneous for every compact XX. And there is a compact pin homogeneous space with points of different π\pi-character.

Keywords

Cite

@article{arxiv.1902.06152,
  title  = {Between homeomorphism type and Tukey type},
  author = {David Milovich},
  journal= {arXiv preprint arXiv:1902.06152},
  year   = {2019}
}

Comments

13 pages

R2 v1 2026-06-23T07:42:44.976Z