The epimorphism relation among countable groups is a complete analytic quasi-order
Logic
2026-04-27 v2 Group Theory
Abstract
We prove that the epimorphism relation is a complete analytic quasi-order on the space of countable groups. In the process, we obtain the result of independent interest that the epimorphism relation on pointed reflexive graphs is complete.
Cite
@article{arxiv.2511.06517,
title = {The epimorphism relation among countable groups is a complete analytic quasi-order},
author = {Su Gao and Feng Li and André Nies and Gianluca Paolini},
journal= {arXiv preprint arXiv:2511.06517},
year = {2026}
}