Karin Schaller (FU Berlin)

Karin Schaller (FU Berlin)

11 June 2020

"Polyhedral Divisors and Orbit Decompositions of Normal Affine Varieties with Torus Action"

Normal affine varieties of dimension n with an effective action of a k-dimensional algebraic torus can be described completely in terms of proper polyhedral divisors living on semiprojective varieties of dimension n−k. We use the language of polyhedral divisors to study the collection of T-orbits and T-orbit closures of a normal affine T-variety in terms of its defining pp-divisor. This is based on previous work of Klaus Altmann and Jürgen Hausen complemented by work in progress with Klaus Altmann.