{ "id": "1202.3222", "version": "v1", "published": "2012-02-15T07:33:12.000Z", "updated": "2012-02-15T07:33:12.000Z", "title": "Pillar switchings and acyclic embedding in mapping class group", "authors": [ "Chan-Seok Jeong", "Yongjin Song" ], "comment": "arXiv admin note: text overlap with arXiv:1005.1300 by other authors", "journal": "Int. J. Math. 24, 1350103 (2013), 21 pages", "doi": "10.1142/S0129167X13501036", "categories": [ "math.AT" ], "abstract": "The braid group $B_g$ is embedded in the ribbon braid group that is defined to be the mapping class group $\\Gamma_{0,(g),1}$. By gluing two copies of surface $S_{0,g+2}$ along $g+1$ holes, we get surface $S_{g,1}$. A pillar switching is a self-homeomorphism of $S_{g,1}$ which switches two pillars of surfaces by $180{}^\\circ$ horizontal rotation. We analyze the actions of pillar switchings on $\\pi_1 S_{g,1}$ and then give concrete expressions of pillar switchings in terms of standard Dehn twists. The map $\\psi: B_g \\rightarrow \\Gamma_{g,1}$ sending the generators of $B_g$ to pillar switchings on $S_{g,1}$ is defined by extending the embedding $B_g \\hookrightarrow \\Gamma_{0,(g+1),1}$. We show that this map is injective by analyzing the actions of pillar switchings on $\\pi_1 S_{g,1}$. The second part of this paper is to prove that this map induces a trivial homology homomorphism in the stable range. For the proof we use the categorical delooping. We construct a suitable monoidal 2-functor from tile category to surface category and show that this functor thus induces a map of double loop spaces.", "revisions": [ { "version": "v1", "updated": "2012-02-15T07:33:12.000Z" } ], "analyses": { "subjects": [ "55P48", "55R37", "57M50" ], "keywords": [ "pillar switching", "mapping class group", "acyclic embedding", "ribbon braid group", "standard dehn twists" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1202.3222J" } } }