The epimorphism relation among countable groups is a complete analytic quasi‐order
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.
Authors
- André Nies (ORCID: https://orcid.org/0000-0002-0666-5180)
- Su Gao (ORCID: https://orcid.org/0000-0002-3570-2008)
- Gianluca Paolini (ORCID: https://orcid.org/0000-0002-8266-362X)
- Feng Li (ORCID: https://orcid.org/0000-0002-5375-2252)
Institutions
- University of Auckland (NZ)
- Nankai University (CN)
- Torino e-district (IT)
- Ospedale San Giuseppe (IT)
Publication Details
- Journal
- Bulletin of the London Mathematical Society
- Published
- 2026-05-01
- DOI
- https://doi.org/10.1112/blms.70375
- Primary Topic
- Advanced Topology and Set Theory
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Istituto Nazionale di Alta Matematica "Francesco Severi"
- National Natural Science Foundation of China
- Marsden Fund
- Fundamental Research Funds for the Central Universities