Abstract
It is shown that the tight closure of a submodule in a Artinian module is the same as its finitistic tight closure, when the modules are graded over a finitely generated N-graded ring over a perfect field. As a corollary, it is deduced that for such a graded ring, strong and weak F-regularity are equivalent. As another application, the following conjecture of Hochster and Huneke is proved: Let (R,m) be a finitely generated N-graded ring over a field with unique homogeneous maximal ideal m, then R is (weakly) F-regular if and only if Rm is (weakly) F-regular.
Original language | English (US) |
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Pages (from-to) | 1279-1290 |
Number of pages | 12 |
Journal | American Journal of Mathematics |
Volume | 121 |
Issue number | 6 |
State | Published - Dec 1 1999 |