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Amir Mafi

Amir Mafi

Academic rank: Professor
ORCID:
Education: PhD.
ScopusId: 14627657300
HIndex:
Faculty: Faculty of Science
Address:
Phone: 33624133

Research

Title
Stability properties of powers of ideals in regular local rings of small dimension
Type
JournalPaper
Keywords
Associated primes, depth stability number
Year
2018
Journal PACIFIC JOURNAL OF MATHEMATICS
DOI
Researchers Jurgen Herzog ، Amir Mafi

Abstract

Let $(R,\mm)$ be a regular local ring or a polynomial ring over a field, and let $I$ be an ideal of $R$ which we assume to be graded if $R$ is a polynomial ring. Let $\astab(I)$, $\overline{\astab}(I)$ and $\dstab(I)$, respectively, be the smallest integer $n$ for which $\Ass(I^n)$, $\Ass(\overline{I^n})$ and $\depth(I^n)$ stabilize. Here $\overline{I^n}$ denotes the integral closure of $I^n$. We show that $\astab(I)=\overline{\astab}(I)=\dstab(I)$ if $\dim R\leq 2$, while already in dimension $3$, $\astab(I)$ and $\overline{\astab}(I)$ may differ by any amount. Moreover, we show that if $\dim R=4$, then there exist ideals $I$ and $J$ such that for any positive integer $c$ one has $\astab(I)-\dstab(I)\geq c$ and $\dstab(J)-\astab(J)\geq c$.