Symplectic birational transformations of the plane
arXiv:1012.0706
Abstract
We study the group of symplectic birational transformations of the plane. It is proved that this group is generated by , the torus and a special map of order , as it was conjectured by A. Usnich. Then we consider a special subgroup , of finite type, defined over any field which admits a surjective morphism to the Thompson group of piecewise linear automorphisms of . We prove that the presentation for this group conjectured by Usnich is correct.
14 pages