Chennai Mathematical Institute


Equations defining symmetric varieties and affine grassmannians
Dr. Andrea Maffei
Universita di Roma "La Sapienza", Italy.


Let s be a simple involution of an algebraic semisimple group G and let H be the subgroup of G of points fixed by s. If the restricted root is of type A, C or BC and G is simply connected or if the restricted root system is of type B and G is adjoint, it is possible to describe a standard monomial theory and the equations of the coordinate ring k[G/H] using the standard monomial theory and the Plucker relations of an appropriate (maybe infinite dimensional) grassmannian.