Hanne Van Den Bosch (Universidad de Chile, Santiago de Chile) will speak in the geometry seminar on Tuesday 17 December 2019 at 11am in the Salle de Profs. Hanne’s title is *Dirac operators describing Graphene Quantum Dots* and her abstract is below.

Low energy electronic excitations in graphene, a two-dimensional lattice
of carbon atoms, are described effectively by a two–dimensional Dirac
operator. For a bounded flake of graphene (a quantum dot), the choice of
boundary conditions determines various properties of the spectrum.
Several of these choices appear in the physics literature on graphene.
For a simply connected flake and a family of boundary conditions, we
obtain an explicit lower bound on the spectral gap around zero. We can
also study the effect of the boundary conditions on eigenvalue sums in
the semiclassical limit.

This is joint work with Rafael Benguria, Edgardo Stockmeyer (PUC, Chile), and Søren
Fournais (Aarhus).