• Title/Summary/Keyword: noetherian modules

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COMMUTATIVE RINGS AND MODULES THAT ARE r-NOETHERIAN

  • Anebri, Adam;Mahdou, Najib;Tekir, Unsal
    • Bulletin of the Korean Mathematical Society
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    • v.58 no.5
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    • pp.1221-1233
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    • 2021
  • In this paper, we introduce and investigate a new class of modules that is closely related to the class of Noetherian modules. Let R be a commutative ring and M be an R-module. We say that M is an r-Noetherian module if every r-submodule of M is finitely generated. Also, we call the ring R to be an r-Noetherian ring if R is an r-Noetherian R-module, or equivalently, every r-ideal of R is finitely generated. We show that many properties of Noetherian modules are also true for r-Noetherian modules. Moreover, we extend the concept of weakly Noetherian rings to the category of modules and we characterize Noetherian modules in terms of r-Noetherian and weakly Noetherian modules. Finally, we use the idealization construction to give non-trivial examples of r-Noetherian rings that are not Noetherian.

On Two Versions of Cohen's Theorem for Modules

  • Xiaolei Zhang;Wei Qi;Hwankoo Kim
    • Kyungpook Mathematical Journal
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    • v.63 no.1
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    • pp.29-36
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    • 2023
  • Parkash and Kour obtained a new version of Cohen's theorem for Noetherian modules, which states that a finitely generated R-module M is Noetherian if and only if for every prime ideal 𝔭 of R with Ann(M) ⊆ 𝔭, there exists a finitely generated submodule N𝔭 of M such that 𝔭M ⊆ N𝔭 ⊆ M(𝔭), where M(𝔭) = {x ∈ M | sx ∈ 𝔭M for some s ∈ R \ 𝔭}. In this paper, we generalize the Parkash and Kour version of Cohen's theorem for Noetherian modules to S-Noetherian modules and w-Noetherian modules.

GRADED w-NOETHERIAN MODULES OVER GRADED RINGS

  • Wu, Xiaoying
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.5
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    • pp.1319-1334
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    • 2020
  • In this paper, we study the basic theory of the category of graded w-Noetherian modules over a graded ring R. Some elementary concepts, such as w-envelope of graded modules, graded w-Noetherian rings and so on, are introduced. It is shown that: (1) A graded domain R is graded w-Noetherian if and only if Rg𝔪 is a graded Noetherian ring for any gr-maximal w-ideal m of R, and there are only finite numbers of gr-maximal w-ideals including a for any nonzero homogeneous element a. (2) Let R be a strongly graded ring. Then R is a graded w-Noetherian ring if and only if Re is a w-Noetherian ring. (3) Let R be a graded w-Noetherian domain and let a ∈ R be a homogeneous element. Suppose 𝖕 is a minimal graded prime ideal of (a). Then the graded height of the graded prime ideal 𝖕 is at most 1.

ON SOME GENERALIZATIONS OF CLOSED SUBMODULES

  • DURGUN, YILMAZ
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.5
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    • pp.1549-1557
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    • 2015
  • Characterizations of closed subgroups in abelian groups have been generalized to modules in essentially dierent ways; they are in general inequivalent. Here we consider the relations between these generalizations over commutative rings, and we characterize the commutative rings over which they coincide. These are exactly the commutative noetherian distributive rings. We also give a characterization of c-injective modules over commutative noetherian distributive rings. For a noetherian distributive ring R, we prove that, (1) direct product of simple R-modules is c-injective; (2) an R-module D is c-injective if and only if it is isomorphic to a direct summand of a direct product of simple R-modules and injective R-modules.

INJECTIVE MODULES OVER ω-NOETHERIAN RINGS, II

  • Zhang, Jun;Wang, Fanggui;Kim, Hwankoo
    • Journal of the Korean Mathematical Society
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    • v.50 no.5
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    • pp.1051-1066
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    • 2013
  • By utilizing known characterizations of ${\omega}$-Noetherian rings in terms of injective modules, we give more characterizations of ${\omega}$-Noetherian rings. More precisely, we show that a commutative ring R is ${\omega}$-Noetherian if and only if the direct limit of GV -torsion-free injective R-modules is injective; if and only if every R-module has a GV -torsion-free injective (pre)cover; if and only if the direct sum of injective envelopes of ${\omega}$-simple R-modules is injective; if and only if the essential extension of the direct sum of GV -torsion-free injective R-modules is the direct sum of GV -torsion-free injective R-modules; if and only if every $\mathfrak{F}_{w,f}(R)$-injective ${\omega}$-module is injective; if and only if every GV-torsion-free R-module admits an $i$-decomposition.

$\mathcal{F}_{\mathcal{S}}$-MITTAG-LEFFLER MODULES AND GLOBAL DIMENSION RELATIVE TO $\mathcal{F}_{\mathcal{S}}$-MITTAG-LEFFLER MODULES

  • Chen, Mingzhao;Wang, Fanggui
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.4
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    • pp.961-976
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    • 2019
  • Let R be any commutative ring and S be any multiplicative closed set. We introduce an S-version of $\mathcal{F}$-Mittag-Leffler modules, called $\mathcal{F}_{\mathcal{S}}$-Mittag-Leffler modules, and define the projective dimension with respect to these modules. We give some characterizations of $\mathcal{F}_{\mathcal{S}}$-Mittag-Leffler modules, investigate the relationships between $\mathcal{F}$-Mittag-Leffler modules and $\mathcal{F}_{\mathcal{S}}$-Mittag-Leffler modules, and use these relations to describe noetherian rings and coherent rings, such as R is noetherian if and only if $R_S$ is noetherian and every $\mathcal{F}_{\mathcal{S}}$-Mittag-Leffler module is $\mathcal{F}$-Mittag-Leffler. Besides, we also investigate the $\mathcal{M}^{\mathcal{F}_{\mathcal{S}}$-global dimension of R, and prove that $R_S$ is noetherian if and only if its $\mathcal{M}^{\mathcal{F}_{\mathcal{S}}$-global dimension is zero; $R_S$ is coherent if and only if its $\mathcal{M}^{\mathcal{F}_{\mathcal{S}}$-global dimension is at most one.

A Note on Noetherian Polynomial Modules

  • Jung Wook Lim
    • Kyungpook Mathematical Journal
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    • v.64 no.3
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    • pp.417-421
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    • 2024
  • Let R be a commutative ring and let M be an R-module. In this note, we give a brief proof of the Hilbert basis theorem for Noetherian modules. This states that if R contains the identity and M is a Noetherian unitary R-module, then M[X] is a Noetherian R[X]-module. We also show that if M[X] is a Noetherian R[X]-module, then M is a Noetherian R-module and there exists an element e ∈ R such that em = m for all m ∈ M. Finally, we prove that if M[X] is a Noetherian R[X]-module and annR(M) = (0), then R has the identity and M is a unitary R-module.