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Related papers: On $\tau_q$-flatness and $\tau_q$-coherence

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Let R be a commutative Noetherian ring. We introduce a theory of formal local cohomology for complexes of R-modules. As an application, we establish some relations between formal local cohomology, local homology, local cohomology and local…

Commutative Algebra · Mathematics 2011-11-30 Mohsen Asgharzadeh , Kamran Divaani-Aazar

Let $R$ be a valuation ring and let $Q$ be its total quotient ring. It is proved that any singly projective (respectively flat) module is finitely projective if and only if $Q$ is maximal (respectively artinian). It is shown that each…

Rings and Algebras · Mathematics 2007-06-04 Francois Couchot

We introduce the notion of the Frobenius--Witt cotangent complex, which can be considered as a derived variant of the module of Frobenius--Witt differentials defined by T. Saito. This new object also can be seen as an arithmetic variant of…

Algebraic Geometry · Mathematics 2026-05-19 Kanau Shimada

It is proved that a module $M$ over a Noetherian local ring $R$ of prime characteristic and positive dimension has finite flat dimension if Tor$_i^R({}^e R, M)=0$ for dim $R$ consecutive positive values of $i$ and infinitely many $e$. Here…

Commutative Algebra · Mathematics 2019-10-11 Taran Funk , Thomas Marley

This paper introduces and studies homological properties of new classes of modules, namely, the $\mathcal F_1$-flat modules and the $\mathcal F_1^{\fp}$-flat modules, where $\mathcal F_1$ stands for the class of right modules of flat…

Commutative Algebra · Mathematics 2020-11-09 Samir Bouchiba , Mouhssine El-Arabi

We show that a ring $R$ is regular if $Tor_{i}^{R}(R^{+},k) = 0$ for some $i\geq 1$ assuming further that $R$ is a $\mathbb{N}$-graded ring of dimension $2$ finitely generated over an equi-characteristic zero field $k$. This answers a…

Commutative Algebra · Mathematics 2022-12-20 Shravan Patankar

In this paper, we introduce and study the $q$-Krull dimension of a commutative ring via its $q$-operation. A new characterization of $\tau_q$-von Neumann regular rings is obtained, and some properties of rings $q$-Krull dimension 0 are…

Commutative Algebra · Mathematics 2024-04-16 Xiaolei Zhang

This survey provides a comprehensive overview of the recent advancements in the theory of ``uniformly $S$''-algebraic structures in commutative ring theory. Originating from the classical concepts of Noetherian, coherent, von Neumann…

Commutative Algebra · Mathematics 2026-02-17 Xiaolei Zhang , Wei Qi

Let $R$ be a commutative ring with identity and $S$ a multiplicative subset of $R$. In this paper, we introduce and study the notions of $S$-pure $S$-exact sequences and $S$-absolutely pure modules which extend the classical notions of pure…

Commutative Algebra · Mathematics 2022-05-25 Xiaolei Zhang

For any ring $R$, we investigate balanced pairs of classes of modules and their relations to cotorsion triples. We characterize the case when a balanced pair generates a tilting cotorsion pair, and dually, when it cogenerates a cotilting…

Representation Theory · Mathematics 2026-02-24 Sergio Estrada , Jiangsheng Hu , Jan Trlifaj

Let $R$ be a ring and $S$ a multiplicative subset of $R$. Then $R$ is called a uniformly $S$-Noetherian ($u$-$S$-Noetherian for abbreviation) ring provided there exists an element $s\in S$ such that for any ideal $I$ of $R$, $sI \subseteq…

Commutative Algebra · Mathematics 2022-01-21 Wei Qi , Hwankoo Kim , Fanggui Wang , Mingzhao Chen , Wei Zhao

In this paper all rings are commutative. We prove some new results on flat epimorphisms of rings and pointwise localizations. Especially among them, it is proved that a ring $R$ is an absolutely flat (von-Neumann regular) ring if and only…

Commutative Algebra · Mathematics 2021-07-27 Abolfazl Tarizadeh

In this paper, we give some new characterizations of $u$-$S$-Noetherian rings and $u$-$S$-coherent rings in terms of uniform $S$-version of injective precovers, flat preenvelopes and absolutely pure modules, respectively. Moreover, we give…

Commutative Algebra · Mathematics 2026-01-06 Xiaolei Zhang , Wei Qi

Over a commutative noetherian ring $R$ of finite Krull dimension, we show that every complex of flat cotorsion $R$-modules decomposes as a direct sum of a minimal complex and a contractible complex. Moreover, we define the notion of a…

Commutative Algebra · Mathematics 2020-07-22 Tsutomu Nakamura , Peder Thompson

A general principle suggests that "anything flat is a directed colimit of countably presentable flats". In this paper, we consider resolutions and coresolutions of modules over a countably coherent ring $R$ (e.g., any coherent ring or any…

Commutative Algebra · Mathematics 2026-02-18 Leonid Positselski

Several authors have introduced various type of coherent-like rings and proved analogous results on these rings. It appears that all these relative coherent rings and all the used techniques can be unified. In [2], several coherent-like…

Commutative Algebra · Mathematics 2020-09-01 Mostafa Amini , Arij Benkhadra , Bennis , Mohammed Hajoui

Let R be a commutative noetherian ring. We give criteria for a complex of cotorsion flat R-modules to be minimal, in the sense that every self homotopy equivalence is an isomorphism. To do this, we exploit Enochs' description of the…

Commutative Algebra · Mathematics 2019-07-15 Peder Thompson

We investigate stable homology of modules over a commutative noetherian ring $R$ with respect to a semidualzing module $C$, and give some vanishing results that improve/extend the known results. As a consequence, we show that the balance of…

Commutative Algebra · Mathematics 2017-09-11 Li Liang

We show that Iacob-Iyengar's answer to a question of Avromov-Foxby extends from Noetherian to coherent rings. In particular, a coherent ring R is regular if and only if the injective (resp. projective) dimension of each complex X of…

Commutative Algebra · Mathematics 2025-03-10 James Gillespie , Alina Iacob

Inspired from the work of P. Scholze on the finiteness of \(\mathbf{F}_{p}\)-cohomology groups of proper rigid-analytic varieties over \(p\)-adic fields, Zavyalov recently introduced the notion of almost coherent rings, which plays a key…

Commutative Algebra · Mathematics 2026-01-21 Xiaolei Zhang