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A series of nonrepresentable relation algebras is constructed from groups. We use them to prove that there are continuum many subvarieties between the variety of representable relation algebras and the variety of coset relation algebras. We…

Logic · Mathematics 2025-02-12 H. Andréka , S. Givant , I. Németi

It is proved that any vertex operator algebra for which the image of the Virasoro element in Zhu's algebra is algebraic over complex numbers is finitely generated. In particular, any vertex operator algebra with a finite dimensional Zhu's…

Quantum Algebra · Mathematics 2008-06-17 Chongying Dong , Wei Zhang

To every finite-dimensional $\mathbb C$-algebra $\Lambda$ of finite representation type we associate an affine variety. These varieties are a large generalization of the varieties defined by "$u$ variables" satisfying "$u$-equations", first…

Representation Theory · Mathematics 2026-01-01 Nima Arkani-Hamed , Hadleigh Frost , Pierre-Guy Plamondon , Giulio Salvatori , Hugh Thomas

A subset S of a group G invariably generates G if G = <s^(g(s)) | s in S> for each choice of g(s) in G, s in S. In this paper we study invariable generation of infinite groups, with emphasis on linear groups. Our main result shows that a…

Group Theory · Mathematics 2014-07-18 William M. Kantor , Alexander Lubotzky , Aner Shalev

Let A be a finitely generated associative algebra over an algebraically closed field. We characterize the finite dimensional modules over A whose orbit closures are regular varieties.

Algebraic Geometry · Mathematics 2007-05-23 Nguyen Quang Loc , Grzegorz Zwara

In this short note we show that every connected reductive simply-connected algebraic group of rank $>1$ over the complex numbers has infinitely many pairs of irreducible representations which are not related by an automorphism of the…

Representation Theory · Mathematics 2026-02-24 Frank Lübeck

We classify essential algebras whose irredundant non-refinable covers consist of primal algebras. The proof is obtained by constructing one to one correspondence between such algebras and partial orders on finite sets. Further, we prove…

Logic · Mathematics 2014-06-26 Shohei Izawa

We establish several finiteness properties of groups defined by algebraic difference equations. One of our main results is that a subgroup of the general linear group defined by possibly infinitely many algebraic difference equations in the…

Algebraic Geometry · Mathematics 2020-07-30 Michael Wibmer

A variety is a category of ordered (finitary) algebras presented by inequations between terms. We characterize categories enriched over the category of posets which are equivalent to a variety. This is quite analogous to Lawvere's classical…

Category Theory · Mathematics 2023-04-03 Jiří Adámek , Jiří Rosický

In this paper, we show that the class of representable residuated semigroups has the finite representation property. That is, every finite representable residuated semigroup is isomorphic to some algebra over a finite base. This result…

Logic · Mathematics 2020-12-11 Daniel Rogozin

We study locally finite varieties (=primitive classes) of linear algebras over finite fields. We do not assume that our algebras are associative or Lie. We are interested in the basic properties of finite algebras in these varieties such…

Rings and Algebras · Mathematics 2026-03-11 Yuri Bahturin , Alexander Olshanskii

Differential algebraic geometry seeks to extend the results of its algebraic counterpart to objects defined by differential equations. Many notions, such as that of a projective algebraic variety, have close differential analogues but their…

Algebraic Geometry · Mathematics 2015-05-14 William D. Simmons

Computation of polynomial relative invariants is a classical tool in algebra. Relative differential invariants are central for the equivalence problem of geometric structures. We address the fundamental problem of finite generation of their…

Differential Geometry · Mathematics 2026-05-19 Boris Kruglikov , Eivind Schneider

This is a survey on the finite basis problem for varieties of algebraic systems. Our exposition is in two directions: (i) We give numerous examples of varieties which are not finitely based. (ii) We give examples of important varieties with…

Rings and Algebras · Mathematics 2026-02-24 Vesselin Drensky

We consider a version of a famous open problem formulated by Kadison, asking whether bounded representations of operator algebras are automatically completely bounded. We investigate this question in the context of amenable operator…

Operator Algebras · Mathematics 2017-08-02 Raphaël Clouâtre , Laurent W. Marcoux

The classical theorem of Weitzenboeck states that the algebra of invariants of a single unipotent transformation $g$ in $GL_m(K)$ acting on the polynomial algebra $K[x_1,...,x_m]$ over a field $K$ of characteristic 0 is finitely generated.…

Rings and Algebras · Mathematics 2007-05-23 Vesselin Drensky

We prove the result in the title. We infer, that unlike cylindric algebras, there is a first order axiomatization of the class of completely representable polyadic algebras of infinite dimension, though the one we obtain is infinite; in…

Logic · Mathematics 2013-06-07 Tarek Sayed Ahmed

In this note we prove that every finite collection of connected algebraic subgroups of the group of triangular automorphisms of the affine space generates a connected solvable algebraic subgroup.

Algebraic Geometry · Mathematics 2022-03-15 Ivan Arzhantsev , Kirill Shakhmatov

In this paper we determine the representation type of some algebras of infinite matrices continuously controlled at infinity by a compact metrizable space. We explicitly classify their finitely presented modules in the finite and tame…

Representation Theory · Mathematics 2007-05-23 Fernando Muro

We prove a finite torsion-free associative conformal algebra to have a finite faithful conformal representation. As a corollary, it is shown that one may join a conformal unit to such an algebra. Some examples are stated to demonstrate that…

Quantum Algebra · Mathematics 2011-08-01 Pavel Kolesnikov