2 papers
math.AG2025
The numerical Amitsur group
Alexander Duncan, Shreya Sharma
The Amitsur subgroup of a variety with a group action measures the failure of the action to lift to the total spaces of its line bundles. We introduce the "numerical Amitsur group,…
math.AG2025
Representations of finite subgroups of Cremona groups
Alexander Duncan, Bailey Heath, Christian Urech
The Cremona group of rank n over a field k is the group of birational automorphisms of the n-dimensional projective space over the field k. We study the minimal dimension such that…