A cohomological invariant of an algebraic group G defined over a field Fwith values in a Galois module C is a morphism of functorsH^1(-,G) –> H^d(-,C) from the category of field extensions of F tothe category of pointed sets. Cohomological invariants of algebraictori and their applications will be discussed. (This is joint workwith S. Blinstein, UCLA.)
- Variétés rationnelles