Squeezed Vacua and the Quantum Statistics of Cosmological Particle Creation

TL;DR

This paper employs squeezed states to systematically analyze how initial quantum states influence particle creation in cosmology, exploring the roles of spontaneous and stimulated processes and their impact on quantum fluctuations.

Contribution

It introduces a comprehensive framework using squeezed states to study initial state dependence and fluctuations in cosmological particle creation, advancing understanding of quantum field behavior in curved spacetime.

Findings

Particle creation varies with initial quantum states.

Spontaneous and stimulated creation are distinguished and analyzed.

Fluctuations in particle number relate to quantum noise and vacuum susceptibility.

Abstract

We use the language of squeezed states to give a systematic description of two issues in cosmological particle creation: a) Dependence of particle creation on the initial state specified. We consider in particular the number state, the coherent and the squeezed state. b) The relation of spontaneous and stimulated particle creation and their dependence on the initial state. We also present results for the fluctuations in particle number in anticipation of its relevance to defining noise in quantum fields and the vacuum susceptibility of spacetime.