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In this article, the projectivity of finitely generated flat modules of a commutative ring are studied from a topological point of view. Then various interesting results are obtained. For instance, it is shown that if a ring has either a…

Commutative Algebra · Mathematics 2019-01-23 Abolfazl Tarizadeh

Using the modern perspective of noncommutative algebraic geometry we survey some recent progress in the theory of stability conditions and moduli spaces with applications in hyperk\"ahler geometry and classical algebraic geometry.

Algebraic Geometry · Mathematics 2026-03-02 Laura Pertusi

The possibility of extending operations of topological and semitopological algebras to their Stone-\v{C}ech compactification and factorization of continuous functions through homomorphisms to metrizable algebras are investigated. Most…

General Topology · Mathematics 2024-06-11 Evgenii Reznichenko

We study the validity of congruence inclusions of the form $ \alpha ( \beta \circ \alpha \gamma \circ \beta \circ \dotsc \circ \alpha \gamma \circ \beta ) \subseteq \alpha \beta \circ \alpha \gamma \circ \alpha \beta \circ \dots$ in…

Rings and Algebras · Mathematics 2020-04-14 Paolo Lipparini

We explore "semibounded" expansions of arbitrary ordered groups; namely, expansions that do not define a field on the whole universe. We show that if $\mathcal R=\langle R, <, +, \dots\rangle$ is a semibounded o-minimal structure and…

Logic · Mathematics 2021-06-24 Pantelis E. Eleftheriou , Alex Savatovsky

This paper explores the cluster algebra structure of the moduli space $\mathscr{A}_{\mathrm{SL}_{n+1},\mathbb{S}}$ of twisted $\mathrm{SL}_{n+1}$-local systems on a surface. We derive general recurrence relations for cluster variables…

Combinatorics · Mathematics 2026-02-27 Vu Tung Lam Dinh , Ivan Chi-Ho Ip

Tannaka duality and its extensions by Lurie, Sch\"appi et al. reveal that many schemes as well as algebraic stacks may be identified with their tensor categories of quasi-coherent sheaves. In this thesis we study constructions of cocomplete…

Algebraic Geometry · Mathematics 2014-10-08 Martin Brandenburg

In this paper we take some classical ideas from commutative algebra, mostly ideas involving duality, and apply them in algebraic topology. To accomplish this we interpret properties of ordinary commutative rings in such a way that they can…

Algebraic Topology · Mathematics 2007-05-23 W. G. Dwyer , J. P. C. Greenlees , S. Iyengar

An algebraic structure is said to be congruence permutable if its arbitrary congruences $\alpha$ and $\beta$ satisfy the equation $\alpha \circ \beta =\beta \circ \alpha$, where $\circ$ denotes the usual composition of binary relations. For…

Group Theory · Mathematics 2018-02-27 Attila Nagy

In this paper, we introduce and investigate \emph{semicorings} over associative semirings and their categories of \emph{semicomodules.} Our results generalize old and recent results on corings over rings and their categories of comodules.…

Rings and Algebras · Mathematics 2013-03-19 Jawad Y. Abuhlail

We present an improved version of commutator methods for unitary operators under a weak regularity condition. Once applied to a unitary operator, the method typically leads to the absence of singularly continuous spectrum and to the local…

Mathematical Physics · Physics 2011-12-02 C. Fernandez , S. Richard , R. Tiedra de Aldecoa

Let $R$ be a commutative ring. We investigate $R$-modules which can be written as \emph{finite} sums of {\it {second}} $R$-submodules (we call them \emph{second representable}). We provide sufficient conditions for an $R$-module $M$ to be…

Commutative Algebra · Mathematics 2017-12-05 Jawad Abuhlail , Hamzah Hroub

In (B-Gran, 2004), was given a categorical formulation of the Shifting Lemma which is a characterization of the Congruence Modular Varieties among all the variety of Universal Algebra, introduced in (Gumm, 1983). Starting from a…

Category Theory · Mathematics 2021-03-24 Dominique Bourn

We introduce a dual Zariski topology on the spectrum of fully coprime $R$-submodules of a given duo module $M$ over an associative (not necessarily commutative) ring $R$. This topology is defined in a way dual to that of defining the…

Rings and Algebras · Mathematics 2010-07-29 Jawad Y. Abuhlail

We introduce some algebraic structures such as singularity, commutators and central extension in modified categories of interest. Additionally, we introduce the cat$^{1}$-objects with their connection to crossed modules in these categories…

Category Theory · Mathematics 2016-02-17 Ahmet Faruk Aslan , Selim Çetin , Enver Önder Uslu

Let R be a commutative ring and let Spec(R) denote the collection of prime ideals of R. We define a topology on Spec(R) by using ultrafilters and demonstrate that this topology is identical to the well known patch or constructible topology.…

Commutative Algebra · Mathematics 2007-10-14 Marco Fontana , K. Alan Loper

In parallel to the classical theory of central extensions of groups, we develop a version for extensions that preserve commutativity. It is shown that the Bogomolov multiplier is a universal object parametrising such extensions of a given…

Group Theory · Mathematics 2015-10-07 Urban Jezernik , Primoz Moravec

Inspired by the commutator and anticommutator algebras derived from algebras graded by groups, we introduce noncommutatively graded algebras. We generalize various classical graded results to the noncommutatively graded situation concerning…

Rings and Algebras · Mathematics 2017-11-01 Patrik Nystedt

This paper is a further contribution to the extensive study by a number of authors of the subalgebra lattice of a Lie algebra. It is shown that, in certain circumstances, including for all solvable algebras, for all Lie algebras over…

Rings and Algebras · Mathematics 2008-06-19 David A. Towers

We study two notions of largeness for closed submodules of Hilbert C*-modules: essentiality and topological essentiality. While the analogous properties are known to be equivalent for closed two-sided ideals of C*-algebras, the one-sided…

Operator Algebras · Mathematics 2026-04-14 Kirill Kartvelishvili