A1 Refereed original research article in a scientific journal
Self-simulable groups
Authors: Barbieri, Sebastián; Sablik, Mathieu; Salo, Ville
Publisher: American Mathematical Society (AMS)
Publication year: 2026
Journal: Transactions of the American Mathematical Society
ISSN: 0002-9947
eISSN: 1088-6850
DOI: https://doi.org/10.1090/tran/9434
Publication's open availability at the time of reporting: No Open Access
Publication channel's open availability : Partially Open Access publication channel
Web address : https://doi.org/10.1090/tran/9434
We say that a finitely generated group Gamma is self-simulable if every effectively closed action of Gamma on a closed subset of {0, 1}N is the topological factor of a Gamma-subshift of finite type. We show that self-simulable groups exist, that any direct product of non-amenable finitely generated groups is self-simulable, that under technical conditions self-simulability is inherited from subgroups, and that the subclass of self-simulable groups is stable under commensurability and quasi-isometries of finitely presented groups. Some notable examples of self-simulable groups obtained are the direct product F-k x F-k of two free groups of rank k > 2, non-amenable finitely generated branch groups, the simple groups of Burger and Mozes, Thompson's V, the groups GL(n)(Z), SLn(Z), Aut(F-n) and Out(F-n) for n > 5; The braid groups B-m for m > 7, and certain classes of RAAGs. We also show that Thompson's F is self-simulable if and only if F is non-amenable, thus giving a computability characterization of this well-known open problem. We also exhibit a few applications of self-simulability on the dynamics of these groups, notably, that every self-simulable group with decidable word problem admits a non-empty strongly aperiodic subshift of finite type.
Funding information in the publication:
The first author was supported by the FONDECYT grants 11200037 and 1240085, and the ANR projects CoCoGro (ANR-16-CE40-0005) and CODYS (ANR-18-CE40-0007). The second author was supported by ANR project Difference (ANR-20-CE40-0002) and the project Computability of asymptotic properties of dynamical systems from CIMI Labex (ANR-11-LABX-0040). The third author was supported by the Academy of Finland project 2608073211.