Strict separation between bounded chaining levels
Construct a measure-class preserving action of a countable group that is $(k+1)$-chaining but not $k$-chaining for some $k$, or at least construct one that is boundedly chaining but not 1-chaining.
References
Is there an mcp \Gamma-action (for some countable group \Gamma) that is (k+1)-chaining but not k-chaining, or at least boundedly chaining but not 1-chaining?
— Bounded chaining in measurable dynamics
(2609.18061 - Tserunyan et al., 16 Sep 2026) in Question q:bbd-C_implies_1-C, Section 1, subsection “Open problems”