Algebraic Geometry Seminar

Rationally connected threefolds and quotients of their groups of birational transformations

Speaker: Egor Yasinski

Location: Warren Weaver Hall 317

Date: Monday, May 13, 2019, 2 p.m.


In this talk, we discuss the structure of birational automorphism groups of rationally connected varieties. In particular, we address a question about the simplicity of these groups. For complex projective plane, the question goes back to Enriques and it was answered only 9 years ago by S. Cantat and S. Lamy. Using some tools from hyperbolic geometry, they proved that the group of birational transformations of the complex projective plane is not simple. Based on a new approach of Blanc–Lamy–Zimmermann, I will explain how to establish this result in all dimensions . Then I will show how to extend authors' techniques even further -- namely, to most del Pezzo fibrations. This is a joint work with Jeremy Blanc.