13,999 research outputs found
Weyl calculus and dual pairs
We consider a dual pair , in the sense of Howe, with compact
acting on for an appropriate via the Weil
Representation. Let be the preimage of in the metaplectic
group. Given a genuine irreducible unitary representation of
we compute the Weyl symbol of orthogonal projection onto
, the -isotypic component. We apply the result to
obtain an explicit formula for the character of the corresponding irreducible
unitary representation of and to compute of the wave
front set of by elementary means
Semisimple orbital integrals on the symplectic space for a real reductive dual pair
We prove a Weyl Harish-Chandra integration formula for the action of a
reductive dual pair on the corresponding symplectic space . As an
intermediate step, we introduce a notion of a Cartan subspace and a notion of
an almost semisimple element in the symplectic space . We prove that the
almost semisimple elements are dense in . Finally, we provide estimates for
the orbital integrals associated with the different Cartan subspaces in
A systematic analysis of X-ray afterglows of gamma-ray burst observed by XMM-Newton
This work is part of a systematic re-analysis program of all the data of
Gamma-Ray Burst (GRB) X-ray afterglows observed so far, in order to constrain
the GRB models. We present here a systematic analysis of those afterglows
observed by XMM-Newton between January 2000 and March 2004. This dataset
includes GRB 011211 and GRB 030329. We have obtained spectra, light curves and
colors for these afterglows. In this paper we focus on the continuum spectral
and temporal behavior. We compare these values with the theoretical ones
expected from the fireball model. We derive constraints about the burst
environment (absorption, density profile) and put constraints on their beaming
angle.Comment: 7 pages, 2 figures, COSPAR proceeding accepted for publication in
Advances in Space Researc
Fiscal Policy and US-Canadian Trade
A factor-augmented vector autoregressive (FAVAR) model is applied to determine the effects of a rise in US government expenditure on the United States and Canadian economies. The results obtained reasonably characterize the effect of a rise in US government spending to the United States and Canadian economies emphasizing the role of the traded goods sector.Factor Model, Principal Component, Government expenditure, VAR.
- …