Math Seminars.
Sándor Kovács (University of Chicago),
Rational Singularities.
A new singularity class is introduced in arbitrary characteristic. In
characteristic 0 these singularities are shown to be equivalent to rational
singularities. As a corollary we obtain a very simple amd natural proof
of Elkik's Theorem: log terminal singularities are rational. Connections
with other flavors of rationality will also be discussed.