
Abstract:In the first part of this talk I will describe some pedagogically motivated work on the electrostatics of topological insulators and on a photonic analog of a topological insulator. In the 1950s Dyson showed that spin-waves in a ferromagnet could be analyzed using a non-hermitian Hamiltonian. In the second part of the talk I will describe how Dyson's method can be more broadly applied to problems of strongly correlated matter.