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Related papers: Flat cotorsion modules over Noether algebras

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Let $A$ be an algebra over a commutative ring $R$. If $R$ is noetherian and $A^\circ$ is pure in $R^A$, then the categories of rational left $A$-modules and right $A^\circ$-comodules are isomorphic. In the Hopf algebra case, we can also…

Rings and Algebras · Mathematics 2007-05-23 J. Y. Abuhlail , J. Gomez-Torrecillas , F. J. Lobillo

Motivated by recent progress in topological data analysis, we establish a Matlis duality between injective hulls and flat covers of persistence modules. This extends to a duality between minimal flat and minimal injective resolutions. We…

Commutative Algebra · Mathematics 2023-10-03 Eero Hyry , Ville Puuska

In this note, some properties of finitely generated two-periodic modules over commutative Noetherian local rings have been studied. We show that under certain assumptions on a pair of modules $\left(M,N \right)$ with $M$ two-periodic, the…

Commutative Algebra · Mathematics 2023-09-08 Nilkantha Das , Sutapa Dey

Let $R$ be a commutative ring. Roughly speaking, we prove that an $R$-module $M$ is flat iff it is a direct limit of $R$-module affine algebraic varieties, and $M$ is a flat Mittag-Leffler module iff it is the union of its $R$-submodule…

Algebraic Geometry · Mathematics 2017-10-12 Carlos Sancho , Fernando Sancho , Pedro Sancho

It is proved that, for a left hereditary ring, an arbitrary left module has a representation in the form of the direct sum of a stable left module and indecomposable projective left modules (if and only if an arbitrary left module has a…

Rings and Algebras · Mathematics 2023-02-23 Dali Zangurashvili

It is proved that a module $M$ over a Noetherian ring $R$ of positive characteristic $p$ has finite flat dimension if there exists an integer $t\ge 0$ such that $\operatorname{Tor}_i^R(M, {}^{f^{e}}\!R)=0$ for $t\le i\le t+\dim R$ and…

Commutative Algebra · Mathematics 2017-05-02 Douglas J. Dailey , Srikanth B. Iyengar , Thomas Marley

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

Silting modules are abundant. Indeed, they parametrise the definable torsion classes over a noetherian ring, and the hereditary torsion pairs of finite type over a commutative ring. Also the universal localisations of a hereditary ring, or…

Representation Theory · Mathematics 2018-01-26 Lidia Angeleri Hügel

The aim of this paper is to describe the classes of strongly flat and weakly cotorsion modules with respect to a multiplicative subset or a finite collection of multiplicative subsets in a commutative ring. The strongly flat modules are…

Commutative Algebra · Mathematics 2019-04-08 Leonid Positselski , Alexander Slavik

Matlis duality for modules over commutative rings gives rise to the notion of Matlis reflexivity. It is shown that Matlis reflexive modules form a Krull-Schmidt category. For noetherian rings the absence of infinite direct sums is a…

Commutative Algebra · Mathematics 2025-06-04 Henning Krause

In recent years, researchers have discovered various large algebraic structures that have surprising finiteness properties, such as FI-modules and Delta-modules. In this paper, we add another example to the growing list: we show that…

Commutative Algebra · Mathematics 2016-03-24 Rohit Nagpal , Steven V Sam , Andrew Snowden

We study some closely interrelated notions of Homological Algebra: (1) We define a topology on modules over a not-necessarily commutative ring $R$ that coincides with the $R$-topology defined by Matlis when $R$ is commutative. (2) We…

Rings and Algebras · Mathematics 2018-08-08 Alberto Facchini , Zahra Nazemian

Let $R$ be a commutative Noetherian ring that is a smooth $\mathbb Z$-algebra. For each ideal $I$ of $R$ and integer $k$, we prove that the local cohomology module $H^k_I(R)$ has finitely many associated prime ideals. This settles a crucial…

Commutative Algebra · Mathematics 2015-06-15 Bhargav Bhatt , Manuel Blickle , Gennady Lyubeznik , Anurag K. Singh , Wenliang Zhang

We introduce a theory of geometry for nonnoetherian commutative algebras with finite Krull dimension. In particular, we establish new notions of normalization and height: depiction (a special noetherian overring) and geometric codimension.…

Algebraic Geometry · Mathematics 2015-12-24 Charlie Beil

In this paper, we study group algebras over which modules have a controlled behaviour with respect to the notions of Gorenstein homological algebra, namely: (a) Gorenstein projective modules are Gorenstein flat, (b) any module whose dual is…

Representation Theory · Mathematics 2025-05-19 Ioannis Emmanouil , Olympia Talelli

We construct the Cartier duality equivalence for affine commutative group schemes $G$ whose coordinate ring is a flat Mittag-Leffler module over an arbitrary base ring $R$. The dual $G^\vee$ of $G$ turns out to be an ind-finite ind-scheme…

Algebraic Geometry · Mathematics 2025-12-17 Dima Arinkin , Joshua Mundinger

We study functors underlying derived Hochschild cohomology, also called Shukla cohomology, of a commutative algebra S essentially of finite type and of finite flat dimension over a commutative noetherian ring K. We construct a complex of…

Commutative Algebra · Mathematics 2009-09-18 Luchezar L. Avramov , Srikanth B. Iyengar , Joseph Lipman , Suresh Nayak

We show that the cosupport of a commutative noetherian ring is precisely the set of primes appearing in a minimal pure-injective resolution of the ring. As an application of this, we prove that every countable commutative noetherian ring…

Commutative Algebra · Mathematics 2018-11-22 Peder Thompson

In this paper we study right $S$-Noetherian rings and modules, extending of notions introduced by Anderson and Dumitrescu in commutative algebra to noncommutative rings. Two characterizations of right $S$-Noetherian rings are given in terms…

Rings and Algebras · Mathematics 2017-08-15 Zehra Bilgin , Manuel L. Reyes , Ünsal Tekir

Let $C$ be a symmetrizable generalized Cartan matrix with symmetrizer $D$ and orientation $\Omega$. In previous work we associated an algebra $H$ to this data, such that the locally free $H$-modules behave in many aspects like…

Representation Theory · Mathematics 2020-08-27 Christof Geiß , Bernard Leclerc , Jan Schröer