Canonical Big Cohen-macaulay Algebras and Rational Singularities
نویسنده
چکیده
We give a canonical construction of a balanced big Cohen-Macaulay algebra for a domain of finite type over C by taking ultraproducts of absolute integral closures in positive characteristic. This yields a new tight closure characterization of rational singularities in characteristic zero.
منابع مشابه
Canonical Big Cohen-Macaulay Algebras with Applications to Singularities
A canonical construction of a balanced big Cohen-Macaulay algebra for a domain of finite type over C is obtained by taking ultraproducts of absolute integral closures in positive characteristic. Among the applications are a new tight closure characterization of rational singularities in characteristic zero, and a necessary condition for Q-Gorenstein logterminal singularities. In particular, it ...
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تاریخ انتشار 2003