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Semisimplicity and global dimension of a finite von Neumann algebra

Lia Vaš (2007)

Mathematica Bohemica

We prove that a finite von Neumann algebra 𝒜 is semisimple if the algebra of affiliated operators 𝒰 of 𝒜 is semisimple. When 𝒜 is not semisimple, we give the upper and lower bounds for the global dimensions of 𝒜 and 𝒰 . This last result requires the use of the Continuum Hypothesis.

Separable and Frobenius monoidal Hom-algebras

Yuanyuan Chen, Xiaoyan Zhou (2014)

Colloquium Mathematicae

As generalizations of separable and Frobenius algebras, separable and Frobenius monoidal Hom-algebras are introduced. They are all related to the Hom-Frobenius-separability equation (HFS-equation). We characterize these two Hom-algebraic structures by the same central element and different normalizing conditions, and the structure of these two types of monoidal Hom-algebras is studied. The Nakayama automorphisms of Frobenius monoidal Hom-algebras are considered.

Separable functors for the category of Doi Hom-Hopf modules

Shuangjian Guo, Xiaohui Zhang (2016)

Colloquium Mathematicae

Let ̃ ( k ) ( H ) A C be the category of Doi Hom-Hopf modules, ̃ ( k ) A be the category of A-Hom-modules, and F be the forgetful functor from ̃ ( k ) ( H ) A C to ̃ ( k ) A . The aim of this paper is to give a necessary and suffcient condition for F to be separable. This leads to a generalized notion of integral. Finally, applications of our results are given. In particular, we prove a Maschke type theorem for Doi Hom-Hopf modules.

Separable K-linear categories

Andrei Chiteș, Costel Chiteș (2010)

Open Mathematics

We define and investigate separable K-linear categories. We show that such a category C is locally finite and that every left C-module is projective. We apply our main results to characterize separable linear categories that are spanned by groupoids or delta categories.

Serre functors for Lie algebras and superalgebras

Volodymyr Mazorchuk, Vanessa Miemietz (2012)

Annales de l’institut Fourier

We propose a new realization, using Harish-Chandra bimodules, of the Serre functor for the BGG category 𝒪 associated to a semi-simple complex finite dimensional Lie algebra. We further show that our realization carries over to classical Lie superalgebras in many cases. Along the way we prove that category 𝒪 and its parabolic generalizations for classical Lie superalgebras are categories with full projective functors. As an application we prove that in many cases the endomorphism algebra of the basic...

Serre Theorem for involutory Hopf algebras

Gigel Militaru (2010)

Open Mathematics

We call a monoidal category C a Serre category if for any C, D ∈ C such that C ⊗ D is semisimple, C and D are semisimple objects in C. Let H be an involutory Hopf algebra, M, N two H-(co)modules such that M ⊗ N is (co)semisimple as a H-(co)module. If N (resp. M) is a finitely generated projective k-module with invertible Hattory-Stallings rank in k then M (resp. N) is (co)semisimple as a H-(co)module. In particular, the full subcategory of all finite dimensional modules, comodules or Yetter-Drinfel’d...

Currently displaying 41 – 60 of 275