Canonical Big Cohen-Macaulay algebras and rational singularities

2002/06/30 by Hans Schoutens · 1 citation
Mathematics · #math.AC #math.AG #msc:13A35

paper · pdf

published as Illinois J. Math. 48 (2004), 131-150 · The second part of the previous version is taken out and is moved to the new paper math.AG/0303189

arxiv created 2003/03/16 · arxiv updated 2009/11/30

Abstract

We give a canonical construction of a balanced big Cohen-Macaulay algebra for a domain of finite type over \mathbb C by taking ultraproducts of absolute integral closures in positive characteristic. This yields a new tight closure characterization of rational singularities in characteristic zero.

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