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Related papers: Classification of pseudo $H$-type algebras

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We show that bounded type implies finite type for a constructible subcategory of the module category of a finitely generated algebra over a field, which is a variant of the first Brauer-Thrall conjecture. A full subcategory is constructible…

Representation Theory · Mathematics 2025-07-31 Kevin Schlegel , Andres Fernandez Herrero

We study simple $\mathfrak{sl}(2)$-modules over $\mathbb C$ that are free of finite rank as $U(\mathfrak h)$-modules, where $\mathfrak h$ is a Cartan subalgebra of $\mathfrak{sl}(2)$. Our main result is an explicit classification of the…

Representation Theory · Mathematics 2026-01-30 Dimitar Grantcharov , Khoa Nguyen , Kaiming Zhao

For any reductive Lie algebra $\mathfrak{g}$ and commutative, associative, unital algebra $S$, we give a complete classification of the simple weight modules of $\mathfrak{g}\otimes S $ with finite weight multiplicities. In particular, any…

Representation Theory · Mathematics 2017-05-12 Michael Lau

As an example of the categorical apparatus of pseudo algebras over 2-theories, we show that pseudo algebras over the 2-theory of categories can be viewed as pseudo double categories with folding or as appropriate 2-functors into…

Category Theory · Mathematics 2011-11-09 Thomas M. Fiore

We classify all equivalences between the indecomposable abelian categories which appear as blocks in BGG category O for reductive Lie algebras. Our classification implies that a block in category O only depends on the Bruhat order of the…

Representation Theory · Mathematics 2019-03-08 Kevin Coulembier

A lexicographic pseudo MV-algebra is an algebra that is isomorphic to an interval in the lexicographic product of a linear unital group with an arbitrary $\ell$-group. We present conditions when a pseudo MV-algebra is lexicographic. We show…

Rings and Algebras · Mathematics 2015-06-11 Anatolij Dvurečenskij

Let $H$ be a finite dimensional semisimple Hopf algebra and $R$ a braided Hopf algebra in the category of Yetter-Drinfeld modules over $H$. When $R$ is a Calabi-Yau algebra, a necessary and sufficient condition for $R#H$ to be a Calabi-Yau…

Quantum Algebra · Mathematics 2011-11-18 Xiaolan Yu , Yinhuo Zhang

Algebras defined over fields of characteristic zero and positive characteristic usually do not behave the same way. However, for certain algebras, for example the group algebras, they behave the same way as the characteristic zero case at…

Representation Theory · Mathematics 2025-02-28 David J. Benson , Kay Jin Lim

It is proved in this paper that for any finite-dimensional nonsemisimple Hopf algebra $A$ there exists a Hopf algebra $H$ containing $A$ as a Hopf subalgebra such that $H$ is not flat over $A$. On the other hand, there is a class of…

Rings and Algebras · Mathematics 2025-06-23 Serge Skryabin

Jensen, Su, and Yang described the projective indecomposable modules of the $0$-Schur algebra $\mathbf{S}_0(n,r)$ using its geometric realization. In this paper, the simple modules of $\mathbf{S}_0(n,r)$ are identified by computing the tops…

Representation Theory · Mathematics 2025-11-18 Woo-Seok Jung , Young-Tak Oh

We prove that the Gerstenhaber bracket on the Hochschild cohomology of the group algebra of a cyclic group over a field of positive characteristic is not trivial. In this case, we relate the Lie algebra structure on the odd degrees of the…

Rings and Algebras · Mathematics 2011-03-17 Selene Sanchez-Flores

This paper aims to describe the restricted Kac modules of restricted Hamiltonian Lie superalgebras of odd type over an algebraically closed field of characteristic $p>3$. In particular, a sufficient and necessary condition for the…

Representation Theory · Mathematics 2018-07-27 Jixia Yuan , Wende Liu

We study gradings by noncommutative groups on finite dimensional Lie algebras over an algebraically closed field of characteristic zero. It is shown that if $L$ is gradeg by a non-abelian finite group $G$ then the solvable radical $R$ of…

Rings and Algebras · Mathematics 2016-02-19 Dušan Pagon , Dušan Repovš , Mikhail Zaicev

It is well-known that the Clifford algebra Cl(2n) can be given a description in terms of creation/annihilation operators acting in the space of inhomogeneous differential forms on C^n. We refer to such inhomogeneous differential forms as…

Mathematical Physics · Physics 2022-05-11 Niren Bhoja , Kirill Krasnov

In this paper, we give a criterion on the semisimplicity of quantized walled Brauer algebras $\mathscr B_{r,s}$ and classify its simple modules over an arbitrary field $\kappa$.

Quantum Algebra · Mathematics 2014-04-01 Hebing Rui , LinLiang Song

We fix a path model for the space of filters of the inverse semigroup $\mathcal{S}_\Lambda$ associated to a left cancellative small category $\Lambda$. Then, we compute its tight groupoid, thus giving a representation of its $C^*$-algebra…

Operator Algebras · Mathematics 2019-06-19 Eduard Ortega , Enrique Pardo

We develop abstract nonsense for module categories over monoidal categories (this is a straightforward categorification of modules over rings). As applications we show that any semisimple monoidal category with finitely many simple objects…

Quantum Algebra · Mathematics 2007-05-23 Viktor Ostrik

Let $R$ be a finite-dimensional algebra over an algebraically closed field $F$ graded by an arbitrary group $G$. We prove that $R$ is a graded division algebra if and only if it is isomorphic to a twisted group algebra of some finite…

Rings and Algebras · Mathematics 2007-05-23 Y. A. Bahturin , S. K. Sehgal , M. V. Zaicev

We classify the category of finite-dimensional real division composition algebras having a non-abelian Lie algebra of derivations. Our complete and explicit classification is largely achieved by introducing the concept of a…

Rings and Algebras · Mathematics 2015-09-18 Seidon Alsaody

Pseudo $H$-type Lie groups $G_{r,s}$ of signature $(r,s)$ are defined via a module action of the Clifford algebra $C\ell_{r,s}$ on a vector space $V \cong \mathbb{R}^{2n}$. They form a subclass of all 2-step nilpotent Lie groups and based…

Analysis of PDEs · Mathematics 2019-01-25 Wolfram Bauer , André Froehly , Irina Markina