Spherical roots of spherical varieties

Toric Degenerations of Spherical Varieties

We prove that any affine, resp. polarized projective, spherical variety admits a flat degeneration to an affine, resp. polarized projective, toric variety. Motivated by Mirror Symmetry, we give conditions for the limit toric variety to be a Gorenstein Fano, and provide many examples. We also provide an explanation for the limits as boundary points of the moduli space of stable pairs whose exist...

Boundedness of Spherical Fano Varieties

Classically, G. Fano proved that the family of (smooth, anticanonically embedded) Fano 3-dimensional varieties is bounded, and moreover provided their classification, later completed by V.A. Iskovskikh, S. Mukai and S. Mori. For singular Fano varieties with log terminal singularities, there are two basic boundedness conjectures: Index Boundedness and the much stronger ǫ-lt Boundedness. The ǫ-lt...

Uniqueness Properties for Spherical Varieties

The goal of these lectures is to explain speaker’s results on uniqueness properties of spherical varieties. By a uniqueness property we mean the following. Consider some special class of spherical varieties. Define some combinatorial invariants for spherical varieties from this class. The problem is to determine whether this set of invariants specifies a spherical variety in this class uniquely...

Intersection Theory on Spherical Varieties

Spherical Varieties and Existence of Invariant K