# Black Hole Squeezers

## TL;DR

This paper demonstrates that black hole quasi-normal modes act as multimode squeezers, amplifying scalar particle production and Hawking radiation through gravitational perturbations.

## Contribution

It introduces the concept that black hole QNMs function as multimode squeezers, linking gravitational perturbations to particle creation and Hawking radiation enhancement.

## Key findings

- QNMs act as multimode squeezers for scalar fields
- Particle production efficiency is higher for lower decaying QNMs
- Gravitational perturbations can amplify Hawking radiation

## Abstract

We show that the gravitational quasi-normal modes (QNMs) of a Schwarzschild black hole play the role of a multimode squeezer that can generate particles. For a minimally coupled scalar field, the QNMs "squeeze" the initial state of the scalar field (even for the vacuum) and produce scalar particles. The maximal squeezing amplitude is inversely proportional to the cube of the imaginary part of the QNM frequency, implying that the particle generation efficiency is higher for lower decaying QNMs. Our results show that the gravitational perturbations can amplify Hawking radiation.