Specialization techniques and stable rationality - Lecture 2the motivic volume formula of Nicaise-Shinder
The talks will be about the use of the motivic obstruction to stable rationality introduced by Nicaise–Shinder to the rationality problem for hypersurfaces and complete intersections. In particular, we will show that very general quartic fivefolds and complete intersections of a quadric and a cubic in $\mathrm{P}^{6}$ arestably irrational. An important new ingredient is the use of tropical degeneration techniques. These results are obtained in collaboration with Johannes Nicaise.