3 papers
math.DS2025
An anti-classification theorem for minimal homeomorphisms on the torus
Bo Peng
We show that it is impossible to classify topological conjugacy relation of minimal homeomorphisms on the torus by countable structures.
math.DS2025
Unbalancedness of the conjugacy relation of ergodic measure-preserving transformations
Bo Peng
We show that the isomorphism of ergodic measure-preserving transformations is not Borel reducible to the relation induced by the conjugacy action of the full group of an ergodic me…
math.DS2025
Anti-classification results for conjugacy of diffeomorphisms on manifolds
Bo Peng
We show that the topological conjugacy relation of diffeomorphisms on any manifold of dimension at least 2 is not classifiable by countable structures. This answers a question of F…