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Moharram Aghapournahr

Moharram Aghapournahr

Academic rank: Associate Professor
ORCID: https://orcid.org/0000-0002-8265-9700
Education: PhD.
ScopusId: 24179345700
Faculty: Science
Address: Arak University
Phone:

Research

Title
Finiteness properties of extension functors of cominimax modules
Type
JournalPaper
Keywords
cominimax modules; local cohomology; Matlis reflexive modules; minimax modules 2020 MATHEMATICS
Year
2021
Journal Communications in Algebra
DOI
Researchers Hamidreza Karimirad ، Moharram Aghapournahr ، KAMAL BAHMANPOUR

Abstract

Let ðR,mÞ be a complete commutative Noetherian local ring, I an ideal of R, M an R-module (not necessarily I-torsion) and N a finitely generated Rmodule with SuppRðNÞ  VðIÞ. It is shown that if M is I-ETH-cominimax (i.e. Exti RðR=I,MÞ is minimax (or Matlis reflexive), for all i  0) and dimM  1 or more generally M 2 FD1, then the R-module ExtnR ðM, NÞ is finitely generated, for all n  0. As an application to local cohomology, let U be a system of ideals of R and I 2 U, if dimM=aM  1 (e.g., dim R=a  1) for all a 2 U, then the R-modules Extj RðHi UðMÞ, NÞ are finitely generated, for all i  0 and j  0. Similar results are true for local cohomology defined by a pair of ideals and ordinary local cohomology modules.