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The Dual Complex of a G-variety

Algebra & Discrete Mathematics

Speaker: Louis Esser, Princeton University
Related Webpage: https://web.math.princeton.edu/~le3339/
Location: 2112 MSB
Start time: Thu, May 30 2024, 1:10PM

We introduce a new invariant of G-varieties, the dual complex, which roughly measures how divisors in the complement of the free locus intersect. We show that the top homology group of this complex is an equivariant birational invariant of G-varieties. As an application, we demonstrate the non-linearizability of certain large abelian group actions on smooth hypersurfaces in projective space of any dimension and degree at least 3.