Artinian cofinite modules over complete Noetherian local rings
Czechoslovak Mathematical Journal, Tome 63 (2013) no. 4, pp. 877-885
Cet article a éte moissonné depuis la source Czech Digital Mathematics Library
Let $(R,\mathfrak {m})$ be a complete Noetherian local ring, $I$ an ideal of $R$ and $M$ a nonzero Artinian $R$-module. In this paper it is shown that if $\mathfrak p$ is a prime ideal of $R$ such that $\dim R/\mathfrak p=1$ and $(0:_M\mathfrak p)$ is not finitely generated and for each $i\geq 2$ the $R$-module ${\rm Ext}^i_R(M,R/\mathfrak p)$ is of finite length, then the $R$-module ${\rm Ext}^1_R(M,R/\mathfrak p)$ is not of finite length. Using this result, it is shown that for all finitely generated $R$-modules $N$ with $\operatorname {Supp}(N)\subseteq V(I)$ and for all integers $i\geq 0$, the $R$-modules ${\rm Ext}^i_R(N,M)$ are of finite length, if and only if, for all finitely generated $R$-modules $N$ with $\operatorname {Supp}(N)\subseteq V(I)$ and for all integers $i\geq 0$, the $R$-modules ${\rm Ext}^i_R(M,N)$ are of finite length.
Let $(R,\mathfrak {m})$ be a complete Noetherian local ring, $I$ an ideal of $R$ and $M$ a nonzero Artinian $R$-module. In this paper it is shown that if $\mathfrak p$ is a prime ideal of $R$ such that $\dim R/\mathfrak p=1$ and $(0:_M\mathfrak p)$ is not finitely generated and for each $i\geq 2$ the $R$-module ${\rm Ext}^i_R(M,R/\mathfrak p)$ is of finite length, then the $R$-module ${\rm Ext}^1_R(M,R/\mathfrak p)$ is not of finite length. Using this result, it is shown that for all finitely generated $R$-modules $N$ with $\operatorname {Supp}(N)\subseteq V(I)$ and for all integers $i\geq 0$, the $R$-modules ${\rm Ext}^i_R(N,M)$ are of finite length, if and only if, for all finitely generated $R$-modules $N$ with $\operatorname {Supp}(N)\subseteq V(I)$ and for all integers $i\geq 0$, the $R$-modules ${\rm Ext}^i_R(M,N)$ are of finite length.
DOI :
10.1007/s10587-013-0059-4
Classification :
13D45, 13E10, 14B15
Keywords: Artinian module; cofinite module; Krull dimension; local cohomology
Keywords: Artinian module; cofinite module; Krull dimension; local cohomology
@article{10_1007_s10587_013_0059_4,
author = {Sadeghi, Behrouz and Bahmanpour, Kamal and A'zami, Jafar},
title = {Artinian cofinite modules over complete {Noetherian} local rings},
journal = {Czechoslovak Mathematical Journal},
pages = {877--885},
year = {2013},
volume = {63},
number = {4},
doi = {10.1007/s10587-013-0059-4},
mrnumber = {3165502},
zbl = {06282116},
language = {en},
url = {http://geodesic.mathdoc.fr/articles/10.1007/s10587-013-0059-4/}
}
TY - JOUR AU - Sadeghi, Behrouz AU - Bahmanpour, Kamal AU - A'zami, Jafar TI - Artinian cofinite modules over complete Noetherian local rings JO - Czechoslovak Mathematical Journal PY - 2013 SP - 877 EP - 885 VL - 63 IS - 4 UR - http://geodesic.mathdoc.fr/articles/10.1007/s10587-013-0059-4/ DO - 10.1007/s10587-013-0059-4 LA - en ID - 10_1007_s10587_013_0059_4 ER -
%0 Journal Article %A Sadeghi, Behrouz %A Bahmanpour, Kamal %A A'zami, Jafar %T Artinian cofinite modules over complete Noetherian local rings %J Czechoslovak Mathematical Journal %D 2013 %P 877-885 %V 63 %N 4 %U http://geodesic.mathdoc.fr/articles/10.1007/s10587-013-0059-4/ %R 10.1007/s10587-013-0059-4 %G en %F 10_1007_s10587_013_0059_4
Sadeghi, Behrouz; Bahmanpour, Kamal; A'zami, Jafar. Artinian cofinite modules over complete Noetherian local rings. Czechoslovak Mathematical Journal, Tome 63 (2013) no. 4, pp. 877-885. doi: 10.1007/s10587-013-0059-4
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