{ "id": "1012.1433", "version": "v1", "published": "2010-12-07T08:57:28.000Z", "updated": "2010-12-07T08:57:28.000Z", "title": "The stable cohomology of automorphisms of free groups with coefficients in the homology representation", "authors": [ "Oscar Randal-Williams" ], "categories": [ "math.AT", "math.GR" ], "abstract": "We study the cohomology of Aut(F_n) and Out(F_n) with coefficients in the modules \\wedge^q H, \\wedge H^*, Sym^q H or Sym^q H^*, where H is the Out(F_n)-module obtained by abelianising the free group F_n. For reasons which are not conceptually clear, taking coefficients in H and its related modules behaves in a far less trivial way than taking coefficients in H^* and its related modules. Based on a conjectural homology stability theorem for spaces of graphs labeled by a simply connected background space, we give a stable integral calculation of these groups in low degrees, and modulo a further conjecture a stable rational calculation in all degrees.", "revisions": [ { "version": "v1", "updated": "2010-12-07T08:57:28.000Z" } ], "analyses": { "subjects": [ "20F28", "20J06", "57R20" ], "keywords": [ "free group", "homology representation", "coefficients", "stable cohomology", "conjectural homology stability theorem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1012.1433R" } } }