• 제목/요약/키워드: w-weak global dimension

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THE w-WEAK GLOBAL DIMENSION OF COMMUTATIVE RINGS

  • WANG, FANGGUI;QIAO, LEI
    • 대한수학회보
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    • 제52권4호
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    • pp.1327-1338
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    • 2015
  • In this paper, we introduce and study the w-weak global dimension w-w.gl.dim(R) of a commutative ring R. As an application, it is shown that an integral domain R is a $Pr\ddot{u}fer$ v-multiplication domain if and only if w-w.gl.dim(R) ${\leq}1$. We also show that there is a large class of domains in which Hilbert's syzygy Theorem for the w-weak global dimension does not hold. Namely, we prove that if R is an integral domain (but not a field) for which the polynomial ring R[x] is w-coherent, then w-w.gl.dim(R[x]) = w-w.gl.dim(R).

REGULARITY RELATIVE TO A HEREDITARY TORSION THEORY FOR MODULES OVER A COMMUTATIVE RING

  • Qiao, Lei;Zuo, Kai
    • 대한수학회지
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    • 제59권4호
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    • pp.821-841
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    • 2022
  • In this paper, we introduce and study regular rings relative to the hereditary torsion theory w (a special case of a well-centered torsion theory over a commutative ring), called w-regular rings. We focus mainly on the w-regularity for w-coherent rings and w-Noetherian rings. In particular, it is shown that the w-coherent w-regular domains are exactly the Prüfer v-multiplication domains and that an integral domain is w-Noetherian and w-regular if and only if it is a Krull domain. We also prove the w-analogue of the global version of the Serre-Auslander-Buchsbaum Theorem. Among other things, we show that every w-Noetherian w-regular ring is the direct sum of a finite number of Krull domains. Finally, we obtain that the global weak w-projective dimension of a w-Noetherian ring is 0, 1, or ∞.

ON 𝜙-w-FLAT MODULES AND THEIR HOMOLOGICAL DIMENSIONS

  • Zhang, Xiaolei;Zhao, Wei
    • 대한수학회보
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    • 제58권4호
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    • pp.1039-1052
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    • 2021
  • In this paper, we introduce and study the class of 𝜙-w-flat modules which are generalizations of both 𝜙-flat modules and w-flat modules. The 𝜙-w-weak global dimension 𝜙-w-w.gl.dim(R) of a commutative ring R is also introduced and studied. We show that, for a 𝜙-ring R, 𝜙-w-w.gl.dim(R) = 0 if and only if w-dim(R) = 0 if and only if R is a 𝜙-von Neumann ring. It is also proved that, for a strongly 𝜙-ring R, 𝜙-w-w.gl.dim(R) ≤ 1 if and only if each nonnil ideal of R is 𝜙-w-flat, if and only if R is a 𝜙-PvMR, if and only if R is a PvMR.

A HOMOLOGICAL CHARACTERIZATION OF PRÜFER v-MULTIPLICATION RINGS

  • Zhang, Xiaolei
    • 대한수학회보
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    • 제59권1호
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    • pp.213-226
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    • 2022
  • Let R be a ring and M an R-module. Then M is said to be regular w-flat provided that the natural homomorphism I ⊗R M → R ⊗R M is a w-monomorphism for any regular ideal I. We distinguish regular w-flat modules from regular flat modules and w-flat modules by idealization constructions. Then we give some characterizations of total quotient rings and Prüfer v-multiplication rings (PvMRs for short) utilizing the homological properties of regular w-flat modules.