{ "id": "math/0104256", "version": "v3", "published": "2001-04-26T22:46:50.000Z", "updated": "2002-04-29T11:31:51.000Z", "title": "Obstructions to positive curvature and symmetry", "authors": [ "Anand Dessai" ], "comment": "21 pages, revised version, new title", "categories": [ "math.DG" ], "abstract": "We show that the indices of certain twisted Dirac operators vanish on a $Spin$-manifold $M$ of positive sectional curvature if the symmetry rank of $M$ is $\\geq 2$ or if the symmetry rank is one and $M$ is two connected. We also give examples of simply connected manifolds of positive Ricci curvature which do not admit a metric of positive sectional curvature and positive symmetry rank.", "revisions": [ { "version": "v3", "updated": "2002-04-29T11:31:51.000Z" } ], "analyses": { "subjects": [ "53C20", "57R20", "53C21", "19L47", "53C27" ], "keywords": [ "positive curvature", "positive sectional curvature", "obstructions", "positive ricci curvature", "positive symmetry rank" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2001math......4256D" } } }