19 Jan 2006; Mat-Nat Faculty (UiTø), room U7=A152. Thursday 10:15-12:00

Valentin Lychagin.

"Introduction to differential invariants - 1".

In these rather elementary lectures I wish to explain extremely important notion of differential invariant. The differential invariants  produce a powerful link between differential geometry and differential equations. This time I shall discuss differential invariants of curves in different plane geometries and related ordinary differential equations. We will study actions of the groups of motions and are-preserving transformations.