{ "id": "2002.02326", "version": "v1", "published": "2020-02-06T16:07:36.000Z", "updated": "2020-02-06T16:07:36.000Z", "title": "Corks, involutions, and Heegaard Floer homology", "authors": [ "Irving Dai", "Matthew Hedden", "Abhishek Mallick" ], "comment": "67 pages", "categories": [ "math.GT" ], "abstract": "Building on the algebraic framework developed by Hendricks, Manolescu, and Zemke, we introduce and study a set of Floer-theoretic invariants aimed at detecting corks. Our invariants obstruct the extension of a given involution over any homology ball, rather than a particular contractible manifold. Unlike previous approaches, we do not utilize any closed 4-manifold topology or contact topology. Instead, we adapt the formalism of local equivalence coming from involutive Heegaard Floer homology. As an application, we define a modification $\\Theta^{\\tau}_{\\mathbb{Z}}$ of the homology cobordism group which takes into account an involution on each homology sphere, and prove that this admits a $\\mathbb{Z}^\\infty$-subgroup of strongly non-extendable corks. The group $\\Theta^{\\tau}_{\\mathbb{Z}}$ can also be viewed as a refinement of the bordism group of diffeomorphisms. Using our invariants, we furthermore establish several new families of corks and prove that various known examples are strongly non-extendable. Our main computational tool is a monotonicity theorem which constrains the behavior of our invariants under equivariant negative-definite cobordisms, and an explicit method of constructing such cobordisms via equivariant surgery.", "revisions": [ { "version": "v1", "updated": "2020-02-06T16:07:36.000Z" } ], "analyses": { "subjects": [ "57M27", "57R58" ], "keywords": [ "involution", "involutive heegaard floer homology", "homology cobordism group", "main computational tool", "equivariant negative-definite cobordisms" ], "note": { "typesetting": "TeX", "pages": 67, "language": "en", "license": "arXiv", "status": "editable" } } }