GRK-Seminar Sommersemester 2025

RTG Seminar Summer term 2025

The Thursday morning seminar (10:15-11:45 in WSC-N-U-3.05) will be the “Research Training Group Seminar” where members of the RTG (PhD students, post-docs,…) present their results. Sometimes, we also have speakers from other places. Depending on the number of speakers and on the proposed topic, a speaker could use one or two sessions.

Abstracts

Gautier Ponsinet: On a characterisation of perfectoid fields by Iwasawa theory

With a p-adic representation of the Galois group of a p-adic field are
associated the Bloch-Kato groups via p-adic Hodge theory. Iwasawa theory
motivates the study of these Bloch-Kato groups over infinite algebraic
extensions of the field of p-adic numbers.
Over perfectoid fields, several results provide a simple and useful
description of the Bloch-Kato groups.
In this talk, we will first present these results. We will then present
a reciprocal statement: the structure of the Bloch-Kato groups
associated with certain de Rham representations characterises the
algebraic extensions of the field of p-adic numbers whose completion is
a perfectoid field. In particular, we will recover, via a different
method, results by Coates and Greenberg for abelian varieties, and by
Bondarko for p-divisible groups.