A stacky approach to crystalline (and prismatic) cohomology.

Vladimir Drinfeld
The University of Chicago; Visiting Professor, School of Mathematics
October 3, 2019

The stacky approach was originated by Bhatt and Lurie. (But the possible mistakes in my talk are mine.)

Let X be a scheme over F_p. Many years ago Grothendieck and Berthelot defined the notion of crystal on X; moreover, they defined the notion of crystalline cohomology of a crystal.