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We construct affine algebras with an arbitrary amount of simple modules of each dimension.

Rings and Algebras · Mathematics 2015-12-17 Be'eri Greenfeld

In this paper, for a given finitely generated algebra (an algebraic structure with arbitrary operations and no predicates) A we study finitely generated limit algebras of A, approaching them via model theory and algebraic geometry. Along…

Algebraic Geometry · Mathematics 2008-08-20 E. Daniyarova , A. Myasnikov , V. Remeslennikov

We construct an example of an $A_{\infty}$ algebra structure defined over a finite dimensional graded vector space.

Algebraic Topology · Mathematics 2010-11-13 Michael P. Allocca , Tom Lada

We study closures of conjugacy classes in the symmetric matrices of the orthogonal group and we determine which one are normal varieties. In contrast to the result for the symplectic group where all classes have normal closure, there is…

Combinatorics · Mathematics 2022-05-11 Marco Trevisiol

We relate the geometry of the resonance varieties associated to a commutative differential graded algebra model of a space to the finiteness properties of the completions of its Alexander-type invariants. We also describe in simple…

Algebraic Geometry · Mathematics 2015-08-04 Alexandru Dimca , Stefan Papadima , Alexandru Suciu

Let $\Bbbk$ be a perfect field with algebraic closure $\overline{\Bbbk}$. If $H$ is a subgroup of plane automorphisms over $\Bbbk$ and $p\in\overline{\Bbbk}^2$ is a point, we describe the subgroup consisting of plane automorphisms which…

Algebraic Geometry · Mathematics 2022-11-08 Iván Pan , Alvaro Rittatore

We describe the finite-dimensional simple modules of all the (twisted and untwisted) multiloop algebras and classify them up to isomorphism.

Representation Theory · Mathematics 2008-12-02 Michael Lau

Faithful representations of regular $\ast$-rings and modular complemented lattices with involution within orthosymmetric sesquilinear spaces are studied within the framework of Universal Algebra. In particular, the correspondence between…

Rings and Algebras · Mathematics 2016-04-26 Christian Herrmann , Marina Semenova

We compute the equivariant fundamental class of the orbit closure of a linear series on the projective line. We also describe the boundary of the orbit closure and how the orbits specialise in one parameter families.

Algebraic Geometry · Mathematics 2022-12-01 Anand Deopurkar , Anand Patel

All simple weight modules with finite dimensional weight spaces over affine Lie algebras are classified.

Representation Theory · Mathematics 2009-10-06 Ivan Dimitrov , Dimitar Grantcharov

We give a necessary and sufficient smoothness condition for the scheme parameterizing the n-dimensional representations of a finitely generated associative algebra over an algebraically closed field of characteristic zero. In particular,…

Algebraic Geometry · Mathematics 2015-10-26 Alessandro Ardizzoni , Federica Galluzzi , Francesco Vaccarino

In this article we study homotopes of finite-dimensional algebras (not necessarily, associative). In the case of associative algebras we study homotopes by methods of Category theory and give description of so-called well-tempered elements…

Rings and Algebras · Mathematics 2020-05-05 Ilya Zhdanovskiy

We give a negative answer to a question by J.M. Landsberg on the nature of normalizations of orbit closures. A counterexample originates from the study of complex, ternary, cubic forms.

Algebraic Geometry · Mathematics 2017-04-11 Jesko Hüttenhain

We explore connected affine algebraic groups $G$, which enjoy the following finiteness property $\rm (F)$: for every algebraic action of $G$, the closure of every $G$-orbit contains only finitely many $G$-orbits. We obtain two main results.…

Algebraic Geometry · Mathematics 2020-04-16 Vladimir L. Popov

In this note, we propose the modular height of an abelian variety defined over a field of finite type over Q. Moreover, we prove its finiteness property.

Number Theory · Mathematics 2007-05-23 Atsushi Moriwaki

Let $H$ be a generalized Liu algebra over an algebraically closed field $k$ of characteristic zero. We prove that all simple Yetter-Drinfeld modules over $H$ are finite-dimensional and present an explicit classification of these modules.…

Quantum Algebra · Mathematics 2026-03-25 Xiangjun Zhen , Gongxiang Liu , Jing Yu

It is proved that for any finite dimensional representation of a prime order group over the field of rational numbers, polynomial invariants of degree at most $3$ separate the orbits. A result providing an upper degree bound for separating…

Commutative Algebra · Mathematics 2025-07-01 Mátyás Domokos

Let $X$ be a finitely generated left module over a left artinian ring $R$, and let $p(X)=\{l_i\}$ be the infinite sequence of nonnegative integers where $l_i$ is the length of the $i$-th term of the minimal projective resolution of $X$. We…

Representation Theory · Mathematics 2007-05-23 Shashidhar Jagadeeshan , Mark Kleiner

We call a finite-dimensional K-algebra A geometrically irreducible if for all d, all connected components of the affine scheme of d-dimensional A-modules are irreducible. We show that the geometrically irreducible algebras without loops…

Representation Theory · Mathematics 2017-09-19 Grzegorz Bobiński , Jan Schröer

For a connected semisimple algebraic group $G$, we consider some special infinite series of tensor products of simple $G$-modules whose $G$-fixed point spaces are at most one-dimensional. We prove that their existence is closely related to…

Representation Theory · Mathematics 2007-06-13 Vladimir L. Popov