Scalar and tensor perturbation in vacuum inflation

TL;DR

This paper analyzes scalar and tensor perturbations in a vacuum inflation model, compares predictions with observations, and finds that the matter produced during inflation aligns with current data.

Contribution

It provides a detailed derivation of perturbations in vacuum inflation and constrains model parameters using recent observational data.

Findings

Perturbations are expressed with Hubble flow-functions.

Model parameters are determined from observational comparison.

Matter density evolution matches current observations.

Abstract

Recently, it was proposed that a small true vacuum universe can inflate spontaneously, in principle. Furthermore, there should be matter creation in vacuum inflation due to quantum fluctuations, and the matter created will influence the inflation simultaneously. In this paper, scalar and tensor perturbations in this model are analyzed and confronted with recent observations. These perturbations are derived and expressed with Hubble flow-functions. By comparing our calculations with experimental results, we can determine all the parameters in this model. Finally, with the determined parameters, we compute the evolution of the matter density and show that the matter produced in inflation roughly fits the observations at present.