English

Quasiorders on topological categories

General Topology 2007-05-23 v1

Abstract

We prove that, for every cardinal number αc\alpha\geq {\mathfrak c}, there exists a metrizable space XX with X=α|X|=\alpha such that for every pair of quasiorders 1\leq_1, 2\leq_2 on a set QQ with Qα|Q| \leq \alpha satisfying the implication q1q    q2qq \leq_1 q' \implies q \leq_2 q' there exists a system {X(q):qQ}\{X(q) : q\in Q\} of non-homeomorphic clopen subsets of XX with the following properties: (1) q1qq \leq_1 q' if and only if X(q)X(q) is homeomorphic to a clopen subset of X(q)X(q'), (2) q2qq \leq_2 q' implies that X(q)X(q) is homeomorphic to a closed subset of X(q)X(q') and (3) ¬(q2q)\neg (q \leq_2 q') implies that there is no one-to-one continuous map of X(q)X(q) into X(q)X(q').

Keywords

Cite

@article{arxiv.math/0204143,
  title  = {Quasiorders on topological categories},
  author = {Vera Trnkova},
  journal= {arXiv preprint arXiv:math/0204143},
  year   = {2007}
}

Comments

10 pages