3 papers
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.DS2025
Toeplitz subshifts of finite rank
Su Gao, Ruiwen Li, Bo Peng +1
In this paper we study some basic problems about Toeplitz subshifts of finite topological rank. We define the notion of a strong Toeplitz subshift of finite rank by combining t…
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.