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Extending the Wedderburn-Artin theory of (classically) semisimple associative rings to the realm of topological rings with right linear topology, we show that the abelian category of left contramodules over such a ring is split…

Category Theory · Mathematics 2022-06-15 Leonid Positselski , Jan Stovicek

For a certain class of abelian categories, we show how to make sense of the "Euler characteristic" of an infinite projective resolution (or, more generally, certain chain complexes that are only bounded above), by passing to a suitable…

Category Theory · Mathematics 2014-02-26 Pramod N. Achar , Catharina Stroppel

In this paper we investigate fixed-point numbers and entropies of endomorphisms on abelian varieties. It was shown quite recently that the number of fixed-points of an iterated endomorphism on a simple complex torus is either periodic or…

Algebraic Geometry · Mathematics 2017-06-20 Thorsten Herrig

It is well-known that the cohomology of symmetric quandles generates robust cocycle invariants for unoriented classical and surface links. Expanding on the recently introduced module-theoretic generalized cohomology for symmetric quandles,…

Quantum Algebra · Mathematics 2025-10-17 Biswadeep Karmakar , Deepanshi Saraf , Mahender Singh

Local and category-theoretical entropies associated with an endomorphism of finite length (i.e., with zero-dimensional closed fiber) of a commutative Noetherian local ring are compared. Local entropy is shown to be less than or equal to…

Commutative Algebra · Mathematics 2018-10-15 Mahdi Majidi-Zolbanin , Nikita Miasnikov

We describe inertial endomorphisms of an abelian group $A$, that is endomorphisms $\varphi$ with the property $|(\varphi(X)+X)/X|<\infty$ for each $X\le A$. They form a ring containing multiplications, the so-called finitary endomorphisms…

Group Theory · Mathematics 2013-10-18 Ulderico Dardano , Silvana Rinauro

The goal of this paper is to characterization generalized Alexander quandles of finite groups in the language of the underlying groups. Firstly, we prove that if finite groups $G$ are simple, then the quandle isomorphic classes of…

Group Theory · Mathematics 2022-11-01 Akihiro Higashitani , Hirotake Kurihara

Let $G=QD_{8k}~$ be the quasi-dihedral group of order $8n$ and $\theta$ be an automorphism of $QD_{8k}$ of finite order. The fixed-point set $H$ of $\theta$ is defined as $H_{\theta}=G^{\theta}=\{x\in G \mid \theta(x)=x\}$ and generalized…

Group Theory · Mathematics 2017-07-05 Zahid Raza , Imran , Bijan Davvaz

For a finite group $G$, we define the inclusion graph of subgroups of $G$, denoted by $\mathcal I(G)$, is a graph having all the proper subgroups of $G$ as its vertices and two distinct vertices $H$ and $K$ in $\mathcal I(G)$ are adjacent…

Group Theory · Mathematics 2016-04-29 P. Devi , R. Rajkumar

In the present paper, we introduce a new concept of convexity which is generated by a family of endomorphisms of an Abelian group. In Abelian groups equipped with a translation invariant metric, we define the boundedness, the norm, the…

Metric Geometry · Mathematics 2020-11-23 Włodzimierz Fechner , Zsolt Páles

For every finite abelian group $G$, there are positive integers $n$ and $d$ such that $G$ is isomorphic to the multiplicative group of $d$-th powers of reduced residues modulo $n$.

Number Theory · Mathematics 2022-11-22 Trevor D. Wooley

A sequence $(a_{n}) $ in an Abelian group is called a $T$-sequence if there exists a Hausdorff group topology on $G$ in which $(a_{n}) $ converges to $0$. For a $T$-sequence $(a_{n}) $, $\tau_{(a_{n}) } $ denotes the strongest group…

General Topology · Mathematics 2019-02-07 D. Dikranjan , I. Protasov

In this paper, we characterize the monoid of endomorphisms of the semigroup of all oriented full transformations of a finite chain, as well as the monoid of endomorphisms of the semigroup of all oriented partial transformations and the…

Rings and Algebras · Mathematics 2022-07-27 De Biao Li , Vítor H. Fernandes

We consider rings whose one-sided ideals are close to automorphism-invariant modules. We study rings in which every (finitely generated) right ideal is automorphism invariant and rings in which every right ideal is a finite direct sum of…

Rings and Algebras · Mathematics 2022-12-13 Adel Abyzov , Truong Cong Quynh , Askar Tuganbaev

Let $G$ be the linear algebraic group $SL_3$ over a field $k$ of characteristic two. Let $A$ be a finitely generated commutative $k$-algebra on which $G$ acts rationally by $k$-algebra automorphisms. We show that the full cohomology ring…

Representation Theory · Mathematics 2007-10-10 Wilberd van der Kallen

We first show that any connected algebraic group over a perfect field is the neutral component of the automorphism group scheme of some normal projective variety. Then we show that very few connected algebraic semigroups can be realized as…

Algebraic Geometry · Mathematics 2013-12-23 Michel Brion

In this paper, we study the relations between groups related to cluster automorphism groups which are defined by Assem, Schiffler and Shamchenko in \cite{ASS}. We establish the relationship among (strict) direct cluster automorphism groups…

Representation Theory · Mathematics 2020-04-14 Fang Li , Siyang Liu

We study Farrell Nil-groups associated to a finite order automorphism of a ring $R$. We show that any such Farrell Nil-group is either trivial, or infinitely generated (as an abelian group). Building on this first result, we then show that…

K-Theory and Homology · Mathematics 2016-01-20 Jean-François Lafont , Stratos Prassidis , Kun Wang

The group isomorphism problem asks whether two finite groups given by their Cayley tables are isomorphic or not. Although there are polynomial-time algorithms for some specific group classes, the best known algorithm for testing isomorphism…

Group Theory · Mathematics 2026-03-10 Saveliy V. Skresanov

Let $A$ be a simple abelian variety of dimension $g$ defined over a finite field $\mathbb{F}_q$ with Frobenius endomorphism $\pi$. This paper describes the structure of the group of rational points $A(\mathbb{F}_{q^n})$, for all $n \geq 1$,…

Number Theory · Mathematics 2021-05-13 Caleb Springer