{ "id": "1604.06551", "version": "v1", "published": "2016-04-22T06:49:02.000Z", "updated": "2016-04-22T06:49:02.000Z", "title": "Crossed modules as maps between connected components of topological groups", "authors": [ "Emmanuel D. Farjoun", "Yoav Segev" ], "comment": "8 pages", "categories": [ "math.AT", "math.GR" ], "abstract": "The purpose of this note is to observe that a homomorphism of discrete groups $f:\\Gamma\\to G$ arises as the induced map $\\pi_0(\\mathfrak{M})\\to \\pi_0(\\mathfrak{X})$ on path components of some closed normal inclusion of topological groups $\\mathfrak{M}\\subseteq \\mathfrak{X},$ if and only if the map $f$ can be equipped with a crossed module structure. In that case an essentially unique realization $\\mathfrak{M}\\subseteq \\mathfrak{X}$ exists by homotopically discrete topological groups.", "revisions": [ { "version": "v1", "updated": "2016-04-22T06:49:02.000Z" } ], "analyses": { "subjects": [ "18G30", "55U10", "57T30" ], "keywords": [ "connected components", "discrete groups", "homotopically discrete topological groups", "crossed module structure", "path components" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160406551F" } } }