4 papers
Characterizing Varieties Using Birational Transformations
Nathan Chen, Louis Esser, Andriy Regeta +2
Suppose is an irreducible complex variety. We show that when is ruled, the group of birational transformations , as a group, determines up to birational transfo…
Asymptotically rigid mapping class groups III: Presentations and isomorphisms
Anthony Genevois, Anne Lonjou, Christian Urech
This article is dedicated to the computation of an explicit presentation of some asymptotically rigid mapping class groups, namely the braided Higman-Thompson groups. To do so, we…
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…
On a Theorem by Lin and Shinder through the Lens of Median Geometry
Anthony Genevois, Anne Lonjou, Christian Urech
Recently, Lin and Shinder constructed non-trivial homomorphisms from Cremona groups of rank >2 to \mathbb{Z} using motivic techniques. In this short note we propose an alternative…