Spectrum of Particles Created in Inhomogeneous Spacetimes

TL;DR

This paper proves that in inhomogeneous spacetimes, the spectrum of scalar particles generated from vacuum approaches a nearly thermal distribution at high momentum, when analyzed via Fourier transform variables.

Contribution

It introduces a rigorous proof that the particle spectrum in inhomogeneous spacetimes becomes nearly thermal at large momenta, expanding understanding of particle creation in complex backgrounds.

Findings

Particle spectrum approaches thermal distribution at high momentum

Spectrum analysis depends on Fourier transform variable

Provides theoretical foundation for particle creation in inhomogeneous spacetimes

Abstract

It is proved that the spectrum of scalar particles generated from the initial vacuum in inhomogeneous spacetime is nearly thermal in the limit of large momentum $k$, if the momentum was defined as the variable of the Fourier transform of the coordinate in the scalar field.