{ "id": "math/0307115", "version": "v2", "published": "2003-07-09T17:07:21.000Z", "updated": "2003-11-28T08:27:17.000Z", "title": "Koszul duality and equivariant cohomology", "authors": [ "Matthias Franz" ], "comment": "12 pages. v2: proof of Theorem 1.2 modified in Sec. 6, references added, other minor changes", "journal": "Documenta Math. 11 (2006), 243-259", "categories": [ "math.AT" ], "abstract": "Let G be a topological group such that its homology H(G) with coefficients in a principal ideal domain R is an exterior algebra, generated in odd degrees. We show that the singular cochain functor carries the duality between G-spaces and spaces over BG to the Koszul duality between modules up to homotopy over H(G) and H^*(BG). This gives in particular a Cartan-type model for the equivariant cohomology of a G-space. As another corollary, we obtain a multiplicative quasi-isomorphism C^*(BG) -> H^*(BG). A key step in the proof is to show that a differential Hopf algebra is formal in the category of A-infinity algebras provided that it is free over R and its homology an exterior algebra.", "revisions": [ { "version": "v2", "updated": "2003-11-28T08:27:17.000Z" } ], "analyses": { "subjects": [ "16S37", "55N91", "16E45", "55N10" ], "keywords": [ "equivariant cohomology", "koszul duality", "singular cochain functor carries", "exterior algebra", "differential hopf algebra" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2003math......7115F" } } }