{ "id": "math/0412057", "version": "v2", "published": "2004-12-02T17:02:33.000Z", "updated": "2005-08-18T20:02:22.000Z", "title": "Conjugation spaces", "authors": [ "Jean-Claude Hausmann", "Tara Holm", "Volker Puppe" ], "comment": "Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-39.abs.html", "journal": "Algebr. Geom. Topol. 5 (2005) 923-964", "categories": [ "math.AT", "math.SG" ], "abstract": "There are classical examples of spaces X with an involution tau whose mod 2-comhomology ring resembles that of their fixed point set X^tau: there is a ring isomorphism kappa: H^2*(X) --> H^*(X^tau). Such examples include complex Grassmannians, toric manifolds, polygon spaces. In this paper, we show that the ring isomorphism kappa is part of an interesting structure in equivariant cohomology called an H^*-frame. An H^*-frame, if it exists, is natural and unique. A space with involution admitting an H^*-frame is called a conjugation space. Many examples of conjugation spaces are constructed, for instance by successive adjunctions of cells homeomorphic to a disk in C^k with the complex conjugation. A compact symplectic manifold, with an anti-symplectic involution compatible with a Hamiltonian action of a torus T, is a conjugation space, provided X^T is itself a conjugation space. This includes the co-adjoint orbits of any semi-simple compact Lie group, equipped with the Chevalley involution. We also study conjugate-equivariant complex vector bundles (`real bundles' in the sense of Atiyah) over a conjugation space and show that the isomorphism kappa maps the Chern classes onto the Stiefel-Whitney classes of the fixed bundle.", "revisions": [ { "version": "v2", "updated": "2005-08-18T20:02:22.000Z" } ], "analyses": { "subjects": [ "55N91", "55M35", "53D05", "57R22" ], "keywords": [ "conjugation space", "study conjugate-equivariant complex vector bundles", "ring isomorphism kappa", "semi-simple compact lie group", "involution" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }