8 Mar 2012; IMS (UiTø), room U1=A228. 15:15-16:30.

Valentin Lychagin

“On Gronwall conjecture”

In 1912 Gronwall conjectured that, in general, a linearization of 3 foliations on the plane (if such possible) is unique up to a projective transformation. It is known today that there are at most 15 such linearizations. I will outline a proof of this conjecture based on the algebras of differential invariants.