The Cremona group is the group of birational transformations of the projective plane, namely isomorphisms between two dense open subsets. This group acts on a CAT(0) cube complex that we constructed with Urech. After an introduction on Cremona group and CAT(0) cube complexes, I will focus on fixed-point property for actions on CAT(0) cube complexes and explain how it is related to an open question for the Cremona group.
Zoom meeting ID: 698 9605 7605
Passcode: A group is called an ________ group if it admits an invariant mean. (8 letters, lowercase)