Matthew Dodelson: Quasinormal ringdown of chaotic systems

I will discuss the late time behavior of thermal correlators in chaotic systems. Under certain assumptions, the thermal two point function exhibits exponential decay, with a discrete spectrum of complex frequencies. I will explain how these frequencies can be thought of as quasinormal modes of a black hole whose radial direction is identified with complexity. This perspective leads to an efficient method for computing the spectrum, and also a better understanding of the analytic structure. I will give various examples, mostly in the context of holography or the SYK model, where explicit computations can be done.