English

Generic dichotomy for homomorphisms for $E_0^\mathbb{N}$

Logic 2024-08-05 v1

Abstract

We prove the following dichotomy. Given an analytic equivalence relation EE, either E0NBE{E_0^{\mathbb{N}}}\leq_B{E} or else any Borel homomorphism from E0NE_0^{\mathbb{N}} to EE is "very far from a reduction", specifically, it factors, on a comeager set, through the projection map (2N)N(2N)k(2^{\mathbb{N}})^{\mathbb{N}}\to (2^{\mathbb{N}})^k for some kNk\in\mathbb{N}. As a corollary, we prove that E0NE_0^{\mathbb{N}} is a prime equivalence relation, answering a question on Clemens.

Cite

@article{arxiv.2408.01261,
  title  = {Generic dichotomy for homomorphisms for $E_0^\mathbb{N}$},
  author = {Assaf Shani},
  journal= {arXiv preprint arXiv:2408.01261},
  year   = {2024}
}
R2 v1 2026-06-28T18:02:16.842Z