Purity for flat cohomology

Name: Purity for flat cohomology
Start: 2019-11-06T15:00:00-05:00
End: 2019-11-06T16:00:00-05:00
Location: Science Center 507

SEMINARS: NUMBER THEORY

When: November 6, 2019

3:00 pm - 4:00 pm

Where: Science Center 507

Address: 1 Oxford Street, Cambridge, MA 02138, United States

Speaker: Kestutis Cesnavicius - CNRS/Paris-Sud

The absolute cohomological purity for étale cohomology of Gabber–Thomasson implies that an étale cohomology class on a regular scheme extends uniquely over a closed subscheme of large codimension. I will discuss the corresponding phenomenon for flat cohomology. The talk is based on joint work with Peter Scholze.