Analog of cosmological particle creation in electromagnetic waveguides

TL;DR

This paper explores how electromagnetic waveguides with time-varying speeds can simulate cosmological particle creation, focusing on the two-point correlation function as a measurable signature of pair production.

Contribution

It introduces the calculation of the two-point correlation function in an electromagnetic waveguide as an analog for cosmological particle creation, highlighting its sensitivity to small perturbations.

Findings

Correlation function shows signatures of particle pair creation.

Observable is first order in perturbation, more detectable for small changes.

Provides a new measurable approach compared to particle number calculations.

Abstract

We consider an electromagnetic waveguide with a time-dependent propagation speed $v(t)$ as an analog for cosmological particle creation. In contrast to most previous studies which focus on the number of particles produced, we calculate the corresponding two-point correlation function. For a small step-like variation $\delta v(t)$, this correlator displays characteristic signatures of particle pair creation. As another potential advantage, this observable is of first order in the perturbation $\delta v(t)$, whereas the particle number is second order in $\delta v(t)$ and thus stronger suppressed for small $\delta v(t)$.