# Talk by Kévin Le Balc'h

On July 5th, 2023, **Kévin Le Balc'h** (Paris Sorbonne Université) gave a talk about **"Observability for Schrödinger equations posed on the whole plane"** as part of the research seminar Analysis of the FernUniversität in Hagen. This lecture is partially supported by the COST action Mathematical models for interacting dynamics on networks.

## Abstract

In this talk, I will present new observability results for Schrödinger equations posed on the whole plane and associated to periodic potentials. More precisely, we aim at establishing observability inequalities from periodic measurable subsets. Thanks to the Floquet-Bloch transform, this problem can be reduced to the study of a family of Schrödinger equations posed on the two-dimensional torus. In order to deal with it, we will adapt a strategy initiated by Bourgain, Burq, Zworski to that context. The main tools would be Strichartz estimates and semi-classical measures that we will introduce in this context. Joint work with Jérémy Martin.