We make use of a well-know deformation of the Poincaré Lie algebra in dimensions ( ) to construct the Poincaré Lie algebra out of the Lie algebras of the de Sitter and anti de Sitter groups, the generators of the Poincaré Lie algebra appearing as certain irrational functions of the generators of the de Sitter groups. We have obtained generalizations of this “anti-deformation” for the and cases ...

This note being devoted to some aspects of the inverse problem of representation theory contains a new insight into it illustrated by two topics. The attention is concentrated on the manner of representation of abstract objects by the concrete ones as well as on the abstract objects themselves. This paper being a continuation of the previous three parts [1] explicates novel features of the gene...

Toroidal Lie algebras are very natural multi-variable generalizations of affine Kac-Moody algebras. The theory of affine Lie algebras is rich and beautiful, having connections with diverse areas of mathematics and physics. Toroidal Lie algebras are also proving themselves to be useful for the applications. Frenkel, Jing and Wang [FJW] used representations of toroidal Lie algebras to construct a...

This paper is about Toroidal Lie algebras which generalize the notion of an Affine Lie algebra. We study Verma type modules for these Toroidal algebras and prove an irreducibility criterion when the number of variables is two. We use the fact that the universal enveloping algebra is an Ore domain to obtain facts about the Verma type modules. Moreover, we are able to characterize the Affine Kac-...

We explain the construction of minimal tilting complexes for objects highest weight categories and we study in detail standard simple objects. For certain representations complex Lie algebras, affine Kac-Moody algebras quantum groups at roots unity, relate multiplicities indecomposable appearing terms these to coefficients Kazhdan-Lusztig polynomials.

In this paper we classify and give Kazhdan-Lusztig type character formulas for equivariantly irreducible representations of Lie algebras reductive algebraic groups over a field large positive characteristic. The equivariance is with respect to group whose connected component torus. Character computation done in two steps. First, treat the case distinguished <inline-formula content-type="math/ma...