| Title: | Finiteness of local homology modules (English) | 
| Author: | Rezaei, Shahram | 
| Language: | English | 
| Journal: | Archivum Mathematicum | 
| ISSN: | 0044-8753 (print) | 
| ISSN: | 1212-5059 (online) | 
| Volume: | 56 | 
| Issue: | 1 | 
| Year: | 2020 | 
| Pages: | 31-41 | 
| Summary lang: | English | 
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| Category: | math | 
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| Summary: | Let $I$ be an ideal of Noetherian ring $R$ and $M$ a finitely generated $R$-module.  In this paper, we     introduce the concept of weakly colaskerian modules and      by using this concept, we give some vanishing and finiteness results for local homology modules.     Let  $I_{M}:=\operatorname{Ann}_{R}(M/IM)$, we will prove that for any integer $n$   \begin{enumerate}  \item[(i)] If $N$ is a weakly colaskerian linearly compact $R$-module  such that $(0:_N {I_M})\neq 0$ then     $$  \operatorname{width}_{I_M}(N)= \inf\{i\mid \operatorname{H}_i^{I_M}(N)\neq   0   \}      =\inf\{i \mid  \operatorname{H}_i^I(M,N)\neq   0   \}\,.  $$       \item[(ii)] If $(R,\frak{m})$ is a Noetherian local ring and $N$ is an artinian $R$-module then  \begin{multline*}  \cup_{i<n}\operatorname{Cos}_R\big(\operatorname{H}_i^{I_M}(N)\big)=\cup_{i<n}\operatorname{Cos}_R\big(\operatorname{H}_i^I(M,N)\big)=\\  \cup_{i<n}\operatorname{Cos}_R\big(\operatorname{Tor}_i^R(M/IM,N)\big)\,,   \end{multline*}  \begin{multline*}                \inf\{i \mid  \operatorname{H}_i^{I_M}(N) \text{ is not Noetherian $R$-module\,} \}=\\ \inf\{i  \mid   \operatorname{H}_i^I(M,N) \mbox{\ is not Noetherian $R$-module\,}\}\,. \end{multline*}  \end{enumerate} (English) | 
| Keyword: | coregular sequence | 
| Keyword: | local homology | 
| Keyword: | weakly colaskerian | 
| MSC: | 13D45 | 
| MSC: | 16E30 | 
| idZBL: | Zbl 07177878 | 
| idMR: | MR4075886 | 
| DOI: | 10.5817/AM2020-1-31 | 
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| Date available: | 2020-03-02T09:06:50Z | 
| Last updated: | 2020-08-26 | 
| Stable URL: | http://hdl.handle.net/10338.dmlcz/148034 | 
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