Extension conjecture for orbit equivalences of cocompact cross sections

Let RdΩ1\mathbb{R}^{d} \curvearrowright \Omega_{1} and RdΩ2\mathbb{R}^{d} \curvearrowright \Omega_{2} be free Borel flows, with d2d \ge 2. Let CiΩi\mathcal{C}_{i} \subseteq \Omega_{i} be cocompact cross sections, and let ζ:C1C2\zeta: \mathcal{C}_{1} \to \mathcal{C}_{2} be an orbit equivalence, meaning a Borel bijection such that

cE1c    ζ(c)E2ζ(c).c E_{1} c' \iff \zeta(c) E_{2} \zeta(c').

Extension conjecture. There exists a smooth equivalence ξ:Ω1Ω2\xi: \Omega_{1} \to \Omega_{2} that extends ζ\zeta. This would establish the possibility of extending orbit equivalences between cross sections to smooth equivalences in the descriptive set-theoretical setting. The cited work constructs such an extension up to a compressible set, while the existence of a complete extension remains open; if always possible, it would imply smooth equivalence of all flows.

Sources & referencesView supporting material

Primary source

Konstantin Slutsky, “Smooth orbit equivalence of multidimensional Borel flows”, arXiv:2101.08411 (2021).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.