{ "id": "math/0607069", "version": "v4", "published": "2006-07-03T21:27:29.000Z", "updated": "2009-06-09T15:03:15.000Z", "title": "Torsion and abelianization in equivariant cohomology", "authors": [ "Tara Holm", "Reyer Sjamaar" ], "comment": "30 pages. References added and typos corrected", "journal": "Transform. Groups 13 (2008), no. 3-4, 585-615", "categories": [ "math.AT", "math.AG", "math.SG" ], "abstract": "Let $X$ be a topological space upon which a compact connected Lie group $G$ acts. It is well-known that the equivariant cohomology $H_G^*(X;\\Q)$ is isomorphic to the subalgebra of Weyl group invariants of the equivariant cohomology $H_T^*(X;\\Q)$, where $T$ is a maximal torus of $G$. This relationship breaks down for coefficient rings $\\k$ other than $\\Q$. Instead, we prove that under a mild condition on $\\k$ the algebra $H_G^*(X,\\k)$ is isomorphic to the subalgebra of $H_T^*(X,\\k)$ annihilated by the divided difference operators.", "revisions": [ { "version": "v4", "updated": "2009-06-09T15:03:15.000Z" } ], "analyses": { "subjects": [ "55N91" ], "keywords": [ "equivariant cohomology", "abelianization", "weyl group invariants", "compact connected lie group", "maximal torus" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......7069H" } } }