{ "id": "math/0112190", "version": "v1", "published": "2001-12-18T21:59:52.000Z", "updated": "2001-12-18T21:59:52.000Z", "title": "Geometry for palindromic automorphism groups of free groups", "authors": [ "Henry H Glover", "Craig A. Jensen" ], "journal": "Comment. Math. Helv. 75 (2000) 644-667", "categories": [ "math.GR", "math.AT" ], "abstract": "We examine the palindromic automorphism group $\\Pi A(F_n)$ of a free group $F_n$, a group first defined by Collins which is related to hyperelliptic involutions of mapping class groups, congruence subgroups of $SL_n(\\Z)$, and symmetric automorphism groups of free groups. Cohomological properties of the group are explored by looking at a contractible space on which $\\Pi A(F_n)$ acts properly with finite quotient. Our results answer some conjectures of Collins and provide a few striking results about the cohomology of $\\Pi A(F_n)$, such as that its rational cohomology is zero at the vcd.", "revisions": [ { "version": "v1", "updated": "2001-12-18T21:59:52.000Z" } ], "analyses": { "subjects": [ "20F32", "20J05", "20F28", "55N91" ], "keywords": [ "palindromic automorphism group", "free group", "symmetric automorphism groups", "hyperelliptic involutions", "rational cohomology" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2001math.....12190G" } } }