{ "id": "2001.02266", "version": "v1", "published": "2020-01-07T20:04:54.000Z", "updated": "2020-01-07T20:04:54.000Z", "title": "On the topology of a resolution of isolated singularities, II", "authors": [ "Vincenzo Di Gennaro", "Davide Franco" ], "comment": "7 pages, no figures", "categories": [ "math.AG" ], "abstract": "Let $Y$ be a complex projective variety of dimension $n$ with isolated singularities, $\\pi:X\\to Y$ a resolution of singularities, $G:=\\pi^{-1}\\left(\\rm{Sing}(Y)\\right)$ the exceptional locus. From the Decomposition Theorem one knows that the map $H^{k-1}(G)\\to H^k(Y,Y\\backslash {\\rm{Sing}}(Y))$ vanishes for $k>n$. It is also known that, conversely, assuming this vanishing one can prove the Decomposition Theorem for $\\pi$ in few pages. The purpose of the present paper is to exhibit a direct proof of the vanishing. As a consequence, it follows a complete and short proof of the Decomposition Theorem for $\\pi$, involving only ordinary cohomology.", "revisions": [ { "version": "v1", "updated": "2020-01-07T20:04:54.000Z" } ], "analyses": { "keywords": [ "isolated singularities", "decomposition theorem", "resolution", "exceptional locus", "complex projective variety" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }