Scalar irreducibility of Eigenspace Representations associated to a symmetric space.
Semigroup actions on homogeneous spaces.
Separately radial and radial Toeplitz operators on the projective space and representation theory
We consider separately radial (with corresponding group ) and radial (with corresponding group symbols on the projective space , as well as the associated Toeplitz operators on the weighted Bergman spaces. It is known that the -algebras generated by each family of such Toeplitz operators are commutative (see R. Quiroga-Barranco and A. Sanchez-Nungaray (2011)). We present a new representation theoretic proof of such commutativity. Our method is easier and more enlightening as it shows that the...
Series of nilpotent orbits.
S-functions and characters of Lie algebras and Lie groups
SL2-triplet associé à un polynôme homogène.
Smooth classification of Cartan actions of higher rank semisimple Lie groups and their lattices.
Smooth components of Springer fibers
This article studies components of Springer fibers for that are associated to closed orbits of on the flag variety of . These components occur in any Springer fiber. In contrast to the case of arbitrary components, these components are smooth varieties. Using results of Barchini and Zierau we show these components are iterated bundles and are stable under the action of a maximal torus of . We prove that if is a line bundle on the flag variety associated to a dominant weight, then the higher...
Some groups whose reduced -algebra is simple
Some special functions related to unimodular pseudo-orthogonal groups
We obtain some matrix elements of basis transformations in a representation space of the unimodular pseudo-orthogonal group. Using these elements, we derive some formulas for special functions.
Sous-groupes paraboliques des groupes classiques et séries complémentaires
Spaces with exceptional fundamental groups.
Spacious Lie groups.
Spectra of self-gradients on spheres.
Spectrum generating on twistor bundle
Spectrum generating technique introduced by Ólafsson, Ørsted, and one of the authors in the paper (Branson, T., Ólafsson, G. and Ørsted, B., Spectrum generating operators, and intertwining operators for representations induced from a maximal parabolic subgroups, J. Funct. Anal. 135 (1996), 163–205.) provides an efficient way to construct certain intertwinors when -types are of multiplicity at most one. Intertwinors on the twistor bundle over have some -types of multiplicity 2. With some additional...
Spherical gradient manifolds
We study the action of a real-reductive group on a real-analytic submanifold of a Kähler manifold. We suppose that the action of extends holomorphically to an action of the complexified group on this Kähler manifold such that the action of a maximal compact subgroup is Hamiltonian. The moment map induces a gradient map . We show that almost separates the –orbits if and only if a minimal parabolic subgroup of has an open orbit. This generalizes Brion’s characterization of spherical...
Spherical harmonics on Grassmannians
We propose a generalization of the theory of spherical harmonics to the context of symmetric subgroups of reductive groups acting on flag manifolds. We give some sample results for the case of the orthogonal group acting on Grassmann manifolds, especially the case of 2-planes.
Spin representations and binary numbers
We consider a construction of the fundamental spin representations of the simple Lie algebras in terms of binary arithmetic of fixed width integers. This gives the spin matrices as a Lie subalgebra of a -graded associative algebra (rather than the usual -filtered Clifford algebra). Our description gives a quick way to write down the spin matrices, and gives a way to encode some extra structure, such as the real structure which is invariant under the compact real form, for some . Additionally...
Spinorial matter and general relativity theory
Stein extensions of Riemann symmetric spaces and some generalization.