Open loci of graded modules

dc.creatorRotthaus, Christel
dc.creatorSega, Liana M.
dc.date2004-03-23
dc.date.accessioned2026-07-07T05:06:41Z
dc.date.available2026-07-07T05:06:41Z
dc.descriptionLet $A=\oplus_{i\in \nn}A_i$ be an excellent homogeneous Noetherian graded ring and let $M=\oplus_{n\in \zz}M_n$ be a finitely generated graded $A$-module. We consider $M$ as a module over $A_0$ and show that the $(S_k)$-loci of $M$ are open in $\Spec(A_0)$. In particular, the Cohen-Macaulay locus $U^0_{CM}=\{\p\in \Spec(A_0) \mid M_\p {is Cohen-Macaulay}\}$ is an open subset of $\Spec(A_0)$. We also show that the $(S_k)$-loci on the homogeneous parts $M_n$ of $M$ are eventually stable. As an application we obtain that for a finitely generated Cohen-Macaulay module $M$ over an excellent ring $A$ and for an ideal $I\subseteq A$ which is not contained in any minimal prime of $M$ the $(S_k)$-loci for the modules $M/I^nM$ are eventually stable.
dc.description22 pages
dc.identifierhttps://arxiv.org/abs/math/0403399
dc.identifierhttp://arxiv.org/abs/math/0403399
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/70566
dc.subjectCommutative Algebra
dc.subjectRings and Algebras
dc.subject13A02, 13H10
dc.titleOpen loci of graded modules
dc.typetext

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