• 제목/요약/키워드: local cohomology

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Results of Graded Local Cohomology Modules with respect to a Pair of Ideals

  • Dehghani-Zadeh, Fatemeh
    • Kyungpook Mathematical Journal
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    • 제58권1호
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    • pp.9-17
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    • 2018
  • Let $R ={\oplus}_{n{\in}Z}R_n$ be a graded commutative Noetherian ring and let I be a graded ideal of R and J be an arbitrary ideal. It is shown that the i-th generalized local cohomology module of graded module M with respect to the (I, J), is graded. Also, the asymptotic behaviour of the homogeneous components of $H^i_{I,J}(M)$ is investigated for some i's with a specified property.

ON ARTINIANNESS OF GENERAL LOCAL COHOMOLOGY MODULES

  • Tri, Nguyen Minh
    • 대한수학회보
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    • 제58권3호
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    • pp.689-698
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    • 2021
  • In this paper, we show some results on the artinianness of local cohomology modules with respect to a system of ideals. If M is a 𝚽-minimax ZD-module, then Hdim M𝚽(M)/𝖆Hdim M𝚽(M) is artinian for all 𝖆 ∈ 𝚽. Moreover, if M is a 𝚽-minimax ZD-module, t is a non-negative integer and Hi𝚽(M) is minimax for all i > t, then Hi𝚽(M) is artinian for all i > t.

FINITENESS PROPERTIES GENERALIZED LOCAL COHOMOLOGY WITH RESPECT TO AN IDEAL CONTAINING THE IRRELEVANT IDEAL

  • Dehghani-Zadeh, Fatemeh
    • 대한수학회지
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    • 제49권6호
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    • pp.1215-1227
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    • 2012
  • The membership of the generalized local cohomology modules $H_a^i$(M,N) of two R-modules M and N with respect to an ideal a in certain Serre subcategories of the category of modules is studied from below ($i<t$). Furthermore, the behaviour of the $n$th graded component $H_a^i(M,N)_n$ of the generalized local cohomology modules with respect to an ideal containing the irrelevant ideal as $n{\rightarrow}-{\infty}$ is investigated by using the above result, in certain graded situations.

COHOMOLOGY OF TORSION AND COMPLETION OF N-COMPLEXES

  • Ma, Pengju;Yang, Xiaoyan
    • 대한수학회지
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    • 제59권2호
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    • pp.379-405
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    • 2022
  • We introduce the notions of Koszul N-complex, Čech N-complex and telescope N-complex, explicit derived torsion and derived completion functors in the derived category DN (R) of N-complexes using the Čech N-complex and the telescope N-complex. Moreover, we give an equivalence between the categories of cohomologically 𝖆-torsion N-complexes and cohomologically 𝖆-adic complete N-complexes, and prove that over a commutative Noetherian ring, via Koszul cohomology, via RHom cohomology (resp. ⊗ cohomology) and via local cohomology (resp. derived completion), all yield the same invariant.

LOCAL-GLOBAL PRINCIPLE AND GENERALIZED LOCAL COHOMOLOGY MODULES

  • Bui Thi Hong Cam;Nguyen Minh Tri;Do Ngoc Yen
    • 대한수학회논문집
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    • 제38권3호
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    • pp.649-661
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    • 2023
  • Let 𝓜 be a stable Serre subcategory of the category of R-modules. We introduce the concept of 𝓜-minimax R-modules and investigate the local-global principle for generalized local cohomology modules that concerns to the 𝓜-minimaxness. We also provide the 𝓜-finiteness dimension f𝓜I (M, N) of M, N relative to I which is an extension the finiteness dimension fI (N) of a finitely generated R-module N relative to I.

SOME FINITENESS RESULTS FOR CO-ASSOCIATED PRIMES OF GENERALIZED LOCAL HOMOLOGY MODULES AND APPLICATIONS

  • Do, Yen Ngoc;Nguyen, Tri Minh;Tran, Nam Tuan
    • 대한수학회지
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    • 제57권5호
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    • pp.1061-1078
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    • 2020
  • We prove some results about the finiteness of co-associated primes of generalized local homology modules inspired by a conjecture of Grothendieck and a question of Huneke. We also show some equivalent properties of minimax local homology modules. By duality, we get some properties of Herzog's generalized local cohomology modules.

COFINITENESS OF GENERAL LOCAL COHOMOLOGY MODULES FOR SMALL DIMENSIONS

  • Aghapournahr, Moharram;Bahmanpour, Kamal
    • 대한수학회보
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    • 제53권5호
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    • pp.1341-1352
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    • 2016
  • Let R be a commutative Noetherian ring, ${\Phi}$ a system of ideals of R and $I{\in}{\Phi}$. In this paper among other things we prove that if M is finitely generated and $t{\in}\mathbb{N}$ such that the R-module $H^i_{\Phi}(M)$ is $FD_{{\leq}1}$ (or weakly Laskerian) for all i < t, then $H^i_{\Phi}(M)$ is ${\Phi}$-cofinite for all i < t and for any $FD_{{\leq}0}$ (or minimax) submodule N of $H^t_{\Phi}(M)$, the R-modules $Hom_R(R/I,H^t_{\Phi}(M)/N)$ and $Ext^1_R(R/I,H^t_{\Phi}(M)/N)$ are finitely generated. Also it is shown that if cd I = 1 or $dimM/IM{\leq}1$ (e.g., $dim\;R/I{\leq}1$) for all $I{\in}{\Phi}$, then the local cohomology module $H^i_{\Phi}(M)$ is ${\Phi}$-cofinite for all $i{\geq}0$. These generalize the main results of Aghapournahr and Bahmanpour [2], Bahmanpour and Naghipour [6, 7]. Also we study cominimaxness and weakly cofiniteness of local cohomology modules with respect to a system of ideals.