Optics, Loss and Gravity

Abstract

We look at some ideas that can be found from making connections among optics, non-Hermitian dynamics and gravity. Using nonlinear optics, we demonstrate how loss can be used to make brighter sources of thermal light. Also, we simulate accelerating Unruh-DeWitt detectors in 1+1 spacetime using a nonlinear-optical setup engineered to have variable dispersion. In our last connection with gravity, we make a connection between a dynamic spacetime metric from linearized gravity and a spacetime-dependent refractive index from a linear-optical setup. From these connections with gravity, we argue that spacetime might be emergent, and that one should not quantize the metric to find a quantum gravity theory. Instead, we propose that gravity might have a gauge theory description and that the problem of quantizing gravity is equivalent to that of quantizing a gauge field. A gauge theory of gravity will make it possible to include this interaction into the Standard Model, and this inclusion may have implications for physics beyond the Standard Model.