Title: Combinatorial automorphisms of spherical varieties
Speaker: Girtrude Hamm
Abstract: Toric varieties are a special class of variety which can be described combinatorialy by lattice fans. Toric morphisms have a neat combinatorial description in terms of lattice homomorphisms. Among other applications, this can be used in classifications to show when the toric varieties of two fans are equivalent. Spherical varieties are a generalisation of toric varieties with a similar combinatorial description. However, the combinatorial description of toric morphisms does not easily generalise to the spherical case. I will give a sketch of how to combinatorialy describe spherical varieties and give examples where the expected notion of morphism breaks down. I will then describe certain ‘good enough’ lattice automorphisms which can be used in classifications of spherical varieties.
Some snacks will be provided before and after the talk.