Coordinates of maximal roots of weakly non-negative unit forms
Given the notion of -structures without torsion on a real dimensional Lie algebra we study the problem of their classification when is a reductive algebra.
In this paper, we develop the crystal basis theory for the quantum queer superalgebra . We define the notion of crystal bases and prove the tensor product rule for -modules in the category . Our main theorem shows that every -module in the category has a unique crystal basis.
We define the -restriction and -induction functors on the category of the cyclotomic rational double affine Hecke algebras. This yields a crystal on the set of isomorphism classes of simple modules, which is isomorphic to the crystal of a Fock space.
In this paper the concepts of mixed cartesian square and quasi-cocartesian square, already known in the category of groups, are adapted to the category of Lie algebras. These concepts can be used in the study of the obstructions of Lie algebra extensions in the same way that Wu has studied the obstructions of group extensions.
Let be a regular prehomogeneous vector space (abbreviated to ), where is a reductive algebraic group over . If is a decomposition of into irreducible representations, then, in general, the PV’s are no longer regular. In this paper we introduce the notion of quasi-irreducible (abbreviated to -irreducible), and show first that for completely -reducible ’s, the -isotypic components are intrinsically defined, as in ordinary representation theory. We also show that, in an appropriate...