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ON BOTT-SAMELSON-DEMAZURE-HANSEN VARIETY

Narasimha Chary
(Chennai Mathematical Institute, India)
Seminar
Onsdag, 16 september, 2015, at 15:30-16:30, in Aud. D3 (1531-215)
Abstrakt:
Let G be a simple algebraic group of adjoint type over the field of complex numbers, let B be a Borel subgroup of G containing a maximal torus T of G, w be an element of the Weyl group W and X(w) be the Schubert variety in the flag variety G/B corresponding to w. Let Z(w; i) be the Bott-Samelson-Demazure-Hansen variety (the desingularization of the Schubert variety X(w)) corresponding to a reduced expression i of w.
In this talk, we will discuss the automorphism group of Z(w; i) and vanishing results for the cohomology of the tangent bundle of Z(w; i). As an application, we see that the varieties Z(w; i) are rigid when G is simply-laced and their deformations are unobstructed in general. Finally, I will state some results on GIT-quotients of the ag variety G/B by a maximal torus.
Organiseret af: QGM
Kontaktperson: Jørgen Ellegaard Andersen