We study analogues of classical inequalities for the eigenvalues of sums of Hermitian matrices for the cone of admissible elements in the pseudo-Hermitian case. In particular, we obtain analogues ofâ€¦ (More)

We present some basic results on a natural Poisson structure on any compact symmetric space. The symplectic leaves of this structure are related to the orbits of the corresponding real semisimpleâ€¦ (More)

We study hamiltonian actions of compact groups in the presence of compatible involutions. We show that the lagrangian fixed point set on the symplectically reduced space is isomorphic to the disjointâ€¦ (More)

Let G be a complex semisimple Lie group and Ï„ a complex antilinear involution that commutes with a Cartan involution. If H denotes the connected subgroup of Ï„ -fixed points in G, and K is maximallyâ€¦ (More)

We consider the moduli space Mr of polygons with fixed side lengths in five-dimensional Euclidean space. We analyze the local structure of its singularities and exhibit a real-analytic equivalenceâ€¦ (More)

We give a simple proof of the equality of the spectra for projections to Levi factors in the linear and non-linear cases, generalizing a classical theorem of Kostant.

Let G be a complex semisimple Lie group and Ï„ a complex an-tilinear involution that commutes with the Cartan involution. If H denotes the connected subgroup of Ï„-fixed points in G, and K is maximallyâ€¦ (More)

The purpose of this note is to define tri-moment maps for certain manifolds with an Sp(1)n-action. We show how these maps can be used to reduce such manifolds to ones with fewer symmetries. Theâ€¦ (More)

Given a compact KÃ¤hler manifold, we consider the complement U of a divisor with normal crossings. We study the variety of unitary representations of Ï€1(U) with certain restrictions related to theâ€¦ (More)