Let G be a complex algebraic group and L an algebraic subgroup of G. The quotient space G/L is called weakly commutative if a generic orbit of the action G : T ∗(G/L) is a coisotropic submanifold. We classify weakly commutative homogeneous spaces N L/L in the case where L is a reductive group and the natural representation L : n/[n, n], where n is the tangent algebra of the group N , is

Let D be a fixed connected component of reductive algebraic group over an algebraically closed field. We use variant the Springer representation to define and study partition into finitely many Strata, one which is open set regular elements. show that Strata are indexed by defined purely in terms Weyl its automorphism D.

The geometric Satake correspondence can be regarded as a construction of rational representations complex connected reductive group $G$. In their study this correspondence, Mirković and Vilonen introduced algebraic cycles that provide linear basis in each irreducible representation. Generalizing construction, Goncharov Shen define tensor product representations. We investigate these bases show ...

Let F be a non-Archimedean locally compact field, let G be a split connected reductive group over F . For a parabolic subgroup Q ⊂ G and a ring L we consider the G-representation on the L-module (∗) C∞(G/Q, L)/ ∑

This paper summarizes the derivation of an explicit and global formula for the character of any holomorphic discrete series representation of a reductive Lie group G which satisfies certain conditions. The only very restrictive condition is that G/K be a Hermitian symmetric space. (Here K is the maximal compact subgroup of G.).

This paper is based on a talk given at the conference ”Representation theory of real reductive groups”, Salt Lake City, July 2009. We fix an algebraically closed field k of characteristic exponent p. (We assume, except in §17, that either p = 1 or p ≫ 0.) We also fix a symmetric space that is a triple (G, θ,K) where G is a connected reductive algebraic group over k, θ : G −→ G is an involution ...

Let $G$ be a reductive $p$-adic group‎. ‎We consider the general question‎ ‎of whether the reducibility of an induced representation can be detected in a‎ ‎``co-rank one‎" ‎situation‎. ‎For smooth complex representations induced from supercuspidal‎ ‎representations‎, ‎we show that a sufficient condition is the existence of a subquotient‎ ‎that does not appear as a subrepresentation‎. ‎An import...

We give an explicit formula for the dimension of the space of G(Fq)-invariant vectors in an irreducible complex representation of G(Fq2), where G is a connected reductive algebraic group defined over a finite field Fq with connected center.

This paper is based on a talk given at the conference ”Representation theory of real reductive groups”, Salt Lake City, July 2009. We fix an algebraically closed field k of characteristic exponent p. (We assume, except in §18, that either p = 1 or p ≫ 0.) We also fix a symmetric space that is a triple (G, θ,K) where G is a connected reductive algebraic group over k, θ : G −→ G is an involution ...

We study homogeneous Lorentzian manifolds M=G/L of a connected reductive Lie group G modulo subgroup L, under the assumption that M is (almost) G-effective and isotropy representation totally reducible. show description such reduces to case semisimple groups G. Moreover, we prove space reductive. describe all reducible subgroups Lorentz divide them into three types. The Type I are compact, whil...