{ "id": "0707.1352", "version": "v2", "published": "2007-07-10T02:09:05.000Z", "updated": "2008-02-19T03:36:12.000Z", "title": "Mixed Lefschetz Theorems and Hodge-Riemann Bilinear Relations", "authors": [ "Eduardo Cattani" ], "comment": "13 pages - Minor revisions. Final version to appear in International Mathematics Research Notices", "categories": [ "math.AG" ], "abstract": "Statements analogous to the Hard Lefschetz Theorem (HLT) and the Hodge-Riemann bilinear relations (HRR) hold in a variety of contexts: they impose restrictions on the cohomology algebra of a smooth compact K\\\"ahler manifold or on the intersection cohomology of a projective toric variety; they restrict the local monodromy of a polarized variation of Hodge structure; they impose conditions on the possible $f$-vectors of convex polytopes. While the statements of these theorems depend on the choice of a K\\\"ahler class, or its analog, there is usually a cone of possible K\\\"ahler classes. It is then natural to ask whether the HLT and HRR remain true in a mixed context. In this note we present a unified approach to proving the mixed HLT and HRR, generalizing the previously known results, and proving it in new cases such as the intersection cohomology of non-rational polytopes.", "revisions": [ { "version": "v2", "updated": "2008-02-19T03:36:12.000Z" } ], "analyses": { "subjects": [ "32G20", "14F43", "32Q15", "52B20" ], "keywords": [ "hodge-riemann bilinear relations", "mixed lefschetz theorems", "intersection cohomology", "hrr remain true", "hard lefschetz theorem" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0707.1352C" } } }