{ "id": "1801.00614", "version": "v1", "published": "2018-01-02T11:35:27.000Z", "updated": "2018-01-02T11:35:27.000Z", "title": "On Bennequin type inequalities for links in tight contact 3-manifolds", "authors": [ "Alberto Cavallo" ], "categories": [ "math.GT" ], "abstract": "We prove that a version of the Thurston-Bennequin inequality holds for Legendrian and transverse links in a rational homology contact 3-sphere $(M,\\xi)$, whenever $\\xi$ is tight. More specifically, we show that the self-linking number of a transverse link $T$ in $(M,\\xi)$, such that the boundary of its tubular neighbourhood consists of incompressible tori, is bounded by the Thurston norm $||T||_T$ of $T$. A similar inequality is given for Legendrian links by using the notions of positive and negative transverse push-off. We apply this bound to compute the tau-invariant for every strongly quasi-positive link in $S^3$. This is done by proving that our inequality is sharp for this family of smooth links.", "revisions": [ { "version": "v1", "updated": "2018-01-02T11:35:27.000Z" } ], "analyses": { "subjects": [ "57M25", "57R17" ], "keywords": [ "bennequin type inequalities", "tight contact", "transverse link", "tubular neighbourhood consists", "rational homology contact" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }