Algebraic Geometry Seminar
Claire Voisin
CNRS and IAS
Decomposition of the diagonal and stable birational invariants
Abstract: The Lüroth problem asks whether a unirational variety
is rational. It has a negative answer starting from dimension 3
and can be attacked by various geometric approaches. For the stable Lüroth
problem, where "rational" is replaced by "stably rational" , only
the Artin-Mumford approach had been used up to now
to solve the problem in dimension 3.
Using the notion of decomposition of the diagonal, we
exhibit many unirational threefolds which are not stably rational
while their Artin-Mumford invariant is trivial.
Wednesday April 1, 2015 at 4:00 PM in SEO 427