{ "id": "2111.10064", "version": "v2", "published": "2021-11-19T06:52:11.000Z", "updated": "2025-01-30T17:54:09.000Z", "title": "Measure equivalence rigidity of the handlebody groups", "authors": [ "Sebastian Hensel", "Camille Horbez" ], "comment": "v2: Revised version after a referee report", "categories": [ "math.GR", "math.GT", "math.OA" ], "abstract": "Let $V$ be a connected $3$-dimensional handlebody of finite genus at least $3$. We prove that the handlebody group $\\mathrm{Mod}(V)$ is superrigid for measure equivalence, i.e. every countable group which is measure equivalent to $\\mathrm{Mod}(V)$ is in fact virtually isomorphic to $\\mathrm{Mod}(V)$. Applications include a rigidity theorem for lattice embeddings of $\\mathrm{Mod}(V)$, an orbit equivalence rigidity theorem for free ergodic measure-preserving actions of $\\mathrm{Mod}(V)$ on standard probability spaces, and a $W^*$-rigidity theorem among weakly compact group actions.", "revisions": [ { "version": "v2", "updated": "2025-01-30T17:54:09.000Z" } ], "analyses": { "keywords": [ "measure equivalence rigidity", "handlebody group", "orbit equivalence rigidity theorem", "standard probability spaces", "free ergodic measure-preserving actions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }