3 papers
math.LO2026
The Conjugacy Relation on One-sided Subshifts is Non-treeable
Ruiwen Li
In this paper we study the conjugacy relation on one-sided subshifts in the viewpoint of descriptive set theory. We show the conjugacy relation on one sided subshifts with the alph…
math.LO2026
Complete orbit equivalence relation and non-universal Polish groups
Longyun Ding, Ruiwen Li, Bo Peng
We show that a non-universal Polish group can induce a complete orbit equivalence relation, which answers a question of Sabok from \cite{OPENPROBLEMS}.
math.LO2024
Isomorphism of pointed minimal systems is not classifiable by countable structures
Ruiwen Li, Bo Peng
We prove that the topological conjugacy relations both for minimal systems and pointed minimal systems are not Borel-reducible to any Borel -action.