{ "id": "1810.04493", "version": "v1", "published": "2018-10-10T12:59:54.000Z", "updated": "2018-10-10T12:59:54.000Z", "title": "Macaulayfication of Noetherian schemes", "authors": [ "Kestutis Cesnavicius" ], "comment": "21 pages", "categories": [ "math.AG", "math.AC", "math.NT" ], "abstract": "To reduce to resolving Cohen-Macaulay singularities, Faltings initiated the program of \"Macaulayfying\" a given Noetherian scheme $X$. For a wide class of $X$, Kawasaki built the sought Cohen-Macaulay modifications, with a crucial drawback that his blowups did not preserve the locus $\\mathrm{CM}(X) \\subset X$ where $X$ is already Cohen-Macaulay. We extend Kawasaki's methods to show that every quasi-excellent, Noetherian scheme $X$ has a Cohen-Macaulay $\\widetilde{X}$ with a proper map $\\widetilde{X} \\rightarrow X$ that is an isomorphism over $\\mathrm{CM}(X)$. This completes Faltings' program, reduces the conjectural resolution of singularities to the Cohen-Macaulay case, and implies that every proper, smooth scheme over a number field has a proper, flat, Cohen-Macaulay model over the ring of integers.", "revisions": [ { "version": "v1", "updated": "2018-10-10T12:59:54.000Z" } ], "analyses": { "subjects": [ "14E15", "13H10", "14B05", "14J17", "14M05" ], "keywords": [ "noetherian scheme", "macaulayfication", "sought cohen-macaulay modifications", "extend kawasakis methods", "wide class" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }