English

$F_\sigma$ equivalence relations and Laver forcing

Logic 2012-11-27 v1 Combinatorics

Abstract

Following the topic of the book Canonical Ramsey Theory on Polish Spaces by V. Kanovei, M. Sabok and J. Zapletal we study Borel equivalences on Laver trees. Here we prove that equivalence relations Borel reducible to an equivalence relation on 2ω2^\omega given by some FσF_\sigma PP-ideal on ω\omega can be canonized to the full equivalence relation or to the identity relation. This has several corollaries, e.g. Silver type dichotomy for the Laver ideal and equivalences Borel reducible to equivalence relations given by FσF_\sigma PP-ideals.

Cite

@article{arxiv.1211.5959,
  title  = {$F_\sigma$ equivalence relations and Laver forcing},
  author = {Michal Doucha},
  journal= {arXiv preprint arXiv:1211.5959},
  year   = {2012}
}
R2 v1 2026-06-21T22:44:06.688Z