TY - JOUR
T1 - Strong and weak F-regularity are equivalent for graded rings
AU - Lyubeznik, Gennady
AU - Smith, Karen E.
PY - 1999/12
Y1 - 1999/12
N2 - 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.
AB - 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.
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U2 - 10.1353/ajm.1999.0042
DO - 10.1353/ajm.1999.0042
M3 - Article
AN - SCOPUS:0033474436
SN - 0002-9327
VL - 121
SP - 1279
EP - 1290
JO - American Journal of Mathematics
JF - American Journal of Mathematics
IS - 6
ER -