{ "id": "2401.02560", "version": "v1", "published": "2024-01-04T22:17:49.000Z", "updated": "2024-01-04T22:17:49.000Z", "title": "Asymptotic dimension and geometric decompositions in dimensions 3 and 4", "authors": [ "H. Contreras Peruyero", "P. Suárez-Serrato" ], "comment": "22 pages, 2 images", "categories": [ "math.GT", "math.DG", "math.GR" ], "abstract": "We show that the fundamental groups of smooth $4$-manifolds that admit geometric decompositions in the sense of Thurston have asymptotic dimension at most four, and equal to 4 when aspherical. We also show that closed $3$-manifold groups have asymptotic dimension at most 3. Our proof method yields that the asymptotic dimension of closed $3$-dimensional Alexandrov spaces is at most 3. We thus obtain that the Novikov conjecture holds for closed $4$-manifolds with such a geometric decomposition and closed $3$-dimensional Alexandrov spaces. Consequences of these results include a vanishing result for the Yamabe invariant of certain $0$-surgered geometric $4$-manifolds and the existence of zero in the spectrum of aspherical smooth $4$-manifolds with a geometric decomposition.", "revisions": [ { "version": "v1", "updated": "2024-01-04T22:17:49.000Z" } ], "analyses": { "keywords": [ "asymptotic dimension", "dimensional alexandrov spaces", "admit geometric decompositions", "proof method yields", "novikov conjecture holds" ], "note": { "typesetting": "TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable" } } }