English
Related papers

Related papers: Classifying approximable algebras

200 papers

In this article, we extend a well known result about real rank zero C* Algebras to higher real rank C* Algebras. The main technique used here is similar to the method in which we approximate continuous functions using projections. What we…

Operator Algebras · Mathematics 2026-04-24 Aranya Sarkar

A reasonably complete theory of the approximation of an irrational by rational fractions whose numerators and denominators lie in prescribed arithmetic progressions is developed in this paper. Results are both, on the one hand, from a…

Number Theory · Mathematics 2014-08-27 Faustin Adiceam

In this paper we generalize cellular algebras by allowing different partial orderings relative to fixed idempotents. For these relative cellular algebras we classify and construct simple modules, and we obtain other characterizations in…

Representation Theory · Mathematics 2023-09-20 Michael Ehrig , Daniel Tubbenhauer

Motivated by an equivalence of categories established by Kapranov and Schechtman, we introduce, for each non-negative integer d, the category of connected bialgebras modulo d+1. We show that these categories fit into an inverse system of…

Quantum Algebra · Mathematics 2025-02-18 Giovanna Carnovale , Francesco Esposito , Lleonard Rubio y Degrassi

We link the recent theory of $L$-algebras to previous notions of Universal Algebra and Categorical Algebra concerning subtractive varieties, commutators, multiplicative lattices, and their spectra. We show that the category of $L$-algebras…

Category Theory · Mathematics 2023-05-31 Alberto Facchini , Marino Gran , Mara Pompili

We prove some strong results on approximation of strongly semistable bundles with vanishing numerical Chern classes by filtrations, whose quotients are line bundles of similar slope. This generalizes some earlier results of…

Algebraic Geometry · Mathematics 2024-11-18 Adrian Langer

By a [$K$-]approximate subring of a ring we mean an additively symmetric subset $X$ such that $X \cdot X \cup (X + X)$ is covered by finitely many [resp.\ $K$] additive translates of $X$. We prove a structure theorem for finite approximate…

Rings and Algebras · Mathematics 2026-04-07 Krzysztof Krupiński , Simon Machado

We show that several Morita equivalence classes of tame algebras do not occur as blocks of finite groups. This refines classifications by Erdmann of classes of blocks with dihedral, semidihedral, and generalised quaternion defect groups. In…

Representation Theory · Mathematics 2021-08-06 Norman Macgregor

We present a classification of $W$ algebras and superalgebras arising in Abelian as well as non Abelian Toda theories. Each model, obtained from a constrained WZW action, is related with an $Sl(2)$ subalgebra (resp. $OSp(1|2)$ superalgebra)…

High Energy Physics - Theory · Physics 2009-10-22 L. Frappat , E. Ragoucy , P. Sorba

We initiate the study of non-semisimple algebras in fusion categories by establishing the framework of $\mathcal{C}$-species -- analogous to the framework of species and quivers used in the study of Artin algebras. Under the (necessary)…

Representation Theory · Mathematics 2026-02-24 Edmund Heng , Mateusz Stroiński

Factorization algebras are local-to-global objects living on manifolds, and they arise naturally in mathematics and physics. Their local structure encompasses examples like associative algebras and vertex algebras; in these examples, their…

Mathematical Physics · Physics 2023-10-30 Kevin Costello , Owen Gwilliam

In this paper, we explore natural connections among the representations of the extended affine Lie algebra $\widehat{sl_N}(\mathbb{C}_q)$ with $\mathbb{C}_q=\mathbb{C}_q[t_0^{\pm1},t_1^{\pm1}]$ an irrational quantum 2-torus, the simple…

Quantum Algebra · Mathematics 2020-04-07 Fulin Chen , Haisheng Li , Shaobin Tan , Qing Wang

We define algebras of quasi-quaternion type, which are symmetric algebras of tame representation type whose stable module category has certain structure similar to that of the algebras of quaternion type introduced by Erdmann. We observe…

Representation Theory · Mathematics 2014-04-29 Sefi Ladkani

This is an informal announcement of results to be described and proved in detail in a paper to appear. We give various results on the structure of approximate subgroups in linear groups such as $\SL_n(k)$. For example, generalising a result…

Group Theory · Mathematics 2010-03-16 Emmanuel Breuillard , Ben Green , Terence Tao

We introduce procellular algebras, so called because they are inverse limits of finite dimensional cellular algebras as defined by Graham and Lehrer. A procellular algebra is defined as a certain completion of an infinite dimensional…

Quantum Algebra · Mathematics 2007-05-23 R. M. Green

The present article is concerned with division algebras that are structurally close to alternative algebras, in the sense that they satisfy some identity or other algebraic property that holds for all alternative division algebras.…

Rings and Algebras · Mathematics 2012-05-30 Erik Darpö , José Maria Pérez Izquierdo

To an abelian category A of homological dimension 1 satisfying certain finiteness conditions, one can associate an algebra, called the Hall algebra. Kapranov studied this algebra when A is the category of coherent sheaves over a smooth…

Quantum Algebra · Mathematics 2007-05-23 Pierre Baumann , Christian Kassel

We introduce a new family of superalgebras which should be considered as a super version of the Khovanov-Lauda-Rouquier algebras. Let $I$ be the set of vertices of a Dynkin diagram with parity. To this data, we associate a family of graded…

Quantum Algebra · Mathematics 2013-03-19 Seok-Jin Kang , Masaki Kashiwara , Shunsuke Tsuchioka

The purpose of this note is to demonstrate the advantages of Y.-Z.~Huang's definition of the Zhu algebra (Comm.\ Contemp.\ Math., 7 (2005), no.~5, 649--706) for an arbitrary vertex algebra, not necessarily equipped with a Hamiltonian…

Quantum Algebra · Mathematics 2026-04-07 Ryo Sato , Shintarou Yanagida

Axial algebras are a recently introduced class of non-associative algebra motivated by applications to groups and vertex-operator algebras. We develop the structure theory of axial algebras focussing on two major topics: (1) radical and…

Rings and Algebras · Mathematics 2020-04-27 Sanhan Khasraw , Justin McInroy , Sergey Shpectorov