Polyhedral divisors and orbit decompositions of normal affine varieties with torus action

Abstract: 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.

algebraic geometrycombinatorics

Audience: researchers in the topic

( slides | video )

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Online Nottingham algebraic geometry seminar

Series comments: Online geometry seminar, typically held on Thursday. This seminar takes place online via Microsoft Teams on the Nottingham University "Algebraic Geometry" team.

For recordings of past talks, copies of the speaker's slides, or to be added to the Team, please visit the seminar homepage at: kasprzyk.work/seminars/ag.html

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