12 Feb 2010; Mat-Nat Faculty (UiTø), seminar room 208 B, Breivang. Friday 14:15-16:00.

Valentin Lychagin

"Binary forms: algebraic versus differential invariants".

In the talk I'll report on joint research with Paul Bibikov (Moscow State University) on SL(2,R)-classification of binary forms.

As far as I know the classification of binary forms, despite its long history, has stopped around degree of binary form equal to 10.

I'll compare differential and algebraic approaches and show how to get a progress by using differential invariants and Lie-Tresse theorem.