Arnab Kundu - 14h00 - Tilting correspondences of perfectoid rings.

We present an alternate proof of a vanishing result of etale cohomology
of perfectoid rings due to Cesnavicius. To establish that, we
prove a tilting equivalence of etale cohomology of perfectoid rings taking
values in commutative, finite etale group schemes. On the way, we
algebraically establish an analogue of the tilting correspondences of
Scholze, between the category of finite etale schemes over a perfectoid
ring and that over its tilt, without using tools from almost ring theory
or adic spaces.