Leeds Logic Seminar, Leeds, May 2026

Abstract: Let $M$ be a countable structure in a countable relational language, let $\mathrm{Aut}(M)$ be its automorphism group, and consider the conjugacy relation on $\mathrm{Aut}(M)$. In this talk we discuss the possible complexities of such an equivalence relation with respect to Borel reducibility.