The Cremona group is compactly presentable
arXiv:1408.4352 · doi:10.1112/jlms/jdv054
Abstract
This article shows that the Cremona group is compactly presentable. To prove this we show that it is a generalised amalgamated product of three of its algebraic subgroups (automorphisms of the plane and Hirzebruch surfaces) divided by one relation.