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We use techniques from both real and complex algebraic geometry to study K-theoretic and related invariants of the algebra C(X) of continuous complex-valued functions on a compact Hausdorff topological space X. For example, we prove a…

Rings and Algebras · Mathematics 2011-03-31 Guillermo Cortiñas , Andreas Thom

We give a survey of the known connections between regularity conditions and amenability conditions in the setting of uniform algebras. For a uniform algebra $A$ we consider the set, $A_{lc}$, of functions in $A$ which are locally constant…

Functional Analysis · Mathematics 2014-12-25 M. J. Heath , J. F. Feinstein

In this paper we will study deformations of A-infinity algebras. We will also answer questions relating to Moore algebras which are one of the simplest nontrivial examples of an A-infinity algebra. We will compute the Hochschild cohomology…

Quantum Algebra · Mathematics 2007-05-23 Alastair Hamilton

A quandle will be called quasi-affine, if it embeds into an affine quandle. Our main result is a characterization of quasi-affine quandles, by group-theoretic properties of their displacement group, by a universal algebraic condition coming…

Group Theory · Mathematics 2018-06-06 Přemysl Jedlička , Agata Pilitowska , David Stanovský , Anna Zamojska-Dzienio

The present paper deals with various aspects of the notion of almost Cohen-Macaulay property, which was introduced and studied by Roberts, Singh and Srinivas. We employ the definition of almost zero modules as defined by a value map, which…

Commutative Algebra · Mathematics 2012-08-28 Mohsen Asgharzadeh , Kazuma Shimomoto

Motivated by work of Barot, Geiss and Zelevinsky, we study a collection of Z-bases (which we call companion bases) of the integral root lattice of a root system of simply-laced Dynkin type. Each companion basis is associated with the quiver…

Representation Theory · Mathematics 2011-11-03 Mark James Parsons

We show that a class of nonrelativistic algebras including non centrally-extended Schrodinger algebra and Galilean Conformal Algebra (GCA) has an affine extension in 2+1 hitherto unknown. This extension arises out of the conformal…

High Energy Physics - Theory · Physics 2014-11-20 Ali Hosseiny , Shahin Rouhani

For a restricted Lie algebra $L$, the conditions under which its restricted enveloping algebra $u(L)$ is semiperfect are investigated. Moreover, it is proved that $u(L)$ is left (or right) perfect if and only if $L$ is finite-dimensional.

Rings and Algebras · Mathematics 2016-10-21 Salvatore Siciliano , Hamid Usefi

This paper concerns homological notions of regularity for noncommutative algebras. Properties of an algebra $A$ are reflected in the regularities of certain (complexes of) $A$-modules. We study the classical Tor-regularity and…

Rings and Algebras · Mathematics 2025-08-07 Ellen Kirkman , Robert Won , James J. Zhang

We study the affine schemes of modules over gentle algebras. We describe the smooth points of these schemes, and we also analyze their irreducible components in detail. Several of our results generalize formerly known results, e.g. by…

Representation Theory · Mathematics 2021-12-23 Christof Geiß , Daniel Labardini-Fragoso , Jan Schröer

We consider Lie algebroids over algebraic spaces (in short we call it as $a$-spaces) by considering the sheaf of Lie-Rinehart algebras. We discuss about properties of universal enveloping algebroid $\mathscr{U}(\mathcal{O}_X,\mathcal{L})$…

Rings and Algebras · Mathematics 2022-11-23 Ashis Mandal , Abhishek Sarkar

We study the interplay between the notions of $n$-coherent rings and finitely $n$-presented modules, and also study the relative homological algebra associated to them. We show that the $n$-coherency of a ring is equivalent to the thickness…

Rings and Algebras · Mathematics 2017-09-05 Daniel Bravo , Marco A. Pérez

In this paper we prove a general result saying that under certain hypothesis an embedding of an affine vertex algebra into an affine $W$--algebra is conformal if and only if their central charges coincide. This result extends our previous…

Representation Theory · Mathematics 2024-08-05 Drazen Adamovic , Pierluigi Moseneder Frajria , Paolo Papi

We study the L-infinity-formality problem for the Hochschild complex of the universal enveloping algebra of some examples of Lie algebras such as Cartan-3-regular quadratic Lie algebras (for example semisimple Lie algebras and in more…

Quantum Algebra · Mathematics 2018-07-10 Martin Bordemann , Olivier Elchinger , Simone Gutt , Abdenacer Makhlouf

We define a new algebra of noncommutative differential forms for any Hopf algebra with an invertible antipode. We prove that there is a one to one correspondence between anti-Yetter-Drinfeld modules, which serve as coefficients for the Hopf…

Quantum Algebra · Mathematics 2009-11-11 Atabey Kaygun , Masoud Khalkhali

We study spaces of conformal blocks associated with line bundles over elliptic curves, with coefficients in a vertex algebra. For vertex algebras satisfying suitable finiteness and semisimplicity conditions, which are met by all admissible…

Quantum Algebra · Mathematics 2026-05-29 Tomoyuki Arakawa , Jethro van Ekeren , Hao Li

We study maximal subalgebras of an arbitrary finite dimensional algebra over a field, and obtain full classification/description results of such algebras. This is done by first obtaining a complete classification in the semisimple case, and…

Rings and Algebras · Mathematics 2017-08-31 Miodrag Iovanov , Alexander Sistko

We show that two cohomological properties of semisimple Lie algebras also hold for Filippov (n-Lie) algebras, namely, that semisimple n-Lie algebras do not admit non-trivial central extensions and that they are rigid i.e., cannot be…

Mathematical Physics · Physics 2009-07-22 Jose A. de Azcarraga , J. M Izquierdo

In this article, we study bounded-below locally finite $\mathbb{Z}$-graded algebras, which are referred to as commonly graded algebras in literature. Commonly graded algebras have almost similar theory as that of connected graded algebras,…

Rings and Algebras · Mathematics 2025-08-11 Haonan Li , Quanshui Wu

It is known that the semi-infinite cohomology spaces of the infinitely twisted nilpotent subalgebra in an affine Lie algebra $g$ with coefficients in an integrable simple module over the affine Lie algebra have a base enumerated by elements…

q-alg · Mathematics 2008-02-03 Sergey Arkhipov