An approach to universality using canonical systems

Math Physics Seminar
Thursday, April 27, 2023 - 1:00pm for 1 hour (actually 50 minutes)
Skiles 005
Milivoje Lukic – Rice University –
Michael Loss

 It is often expected that the local statistical behavior of eigenvalues of some system depends only on its local properties; for instance, the local distribution of zeros of orthogonal polynomials should depend only on the local properties of the measure of orthogonality. This phenomenon is studied using an object called the Christoffel-Darboux kernel. The most commonly studied case is known as bulk universality, where the rescaled limit of Christoffel-Darboux kernels converges to the sine kernel. We will present a new approach which gives for the first time a completely local sufficient condition for bulk universality. This approach is based on a matrix version of the Christoffel-Darboux kernel and the de Branges theory of canonical systems, and it applies to other self-adjoint systems with 2x2 transfer matrices such as continuum Schrodinger and Dirac operators. The talk is based on joint work with Benjamin Eichinger (Technical University Wien) and Brian Simanek (Baylor University).