Smooth Projective Symmetric Varieties with Picard Number equal to one
arXiv:math/0702340
Abstract
We classify the smooth projective symmetric G-varieties with Picard number one (and G semisimple). Moreover we prove a criterion for the smoothness of the simple (normal) symmetric varieties whose closed orbit is complete. In particular we prove that, given a such variety X which is not exceptional, then X is smooth if and only if an appropriate toric variety contained in X is smooth.
23 pages; some minor errors corrected, final version. To appear on "International Journal of Mathematics"