{ "id": "1205.1606", "version": "v1", "published": "2012-05-08T07:15:56.000Z", "updated": "2012-05-08T07:15:56.000Z", "title": "The braidings in the mapping class groups of surfaces", "authors": [ "Yongjin Song" ], "comment": "11pages, 10 figures", "categories": [ "math.AT" ], "abstract": "The disjoint union of mapping class groups of surfaces forms a braided monoidal category $\\mathcal M$, as the disjoint union of the braid groups $\\mathcal B$ does. We give a concrete, and geometric meaning of the braiding $\\beta_{r,s}$ in $\\M$. Moreover, we find a set of elements in the mapping class groups which correspond to the standard generators of the braid groups. Using this, we obtain an obvious map $\\phi:B_g\\ra\\Gamma_{g,1}$. We show that this map $\\phi$ is injective and nongeometric in the sense of Wajnryb. Since this map extends to a braided monoidal functor $\\Phi : \\mathcal B \\rightarrow \\mathcal M$, the integral homology homomorphism induced by $\\phi$ is trivial in the stable range.", "revisions": [ { "version": "v1", "updated": "2012-05-08T07:15:56.000Z" } ], "analyses": { "subjects": [ "55R37", "18D10", "57M50" ], "keywords": [ "mapping class groups", "braid groups", "disjoint union", "surfaces forms", "standard generators" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.1606S" } } }