Inflationary gravitational waves in collapse scheme models

TL;DR

This paper investigates the generation of primordial gravitational waves in inflationary models incorporating a self-induced collapse of the wave function, extending previous scalar-focused analyses to include tensor perturbations within a joint metric-matter quantization framework.

Contribution

It provides the first calculation of the tensor power spectrum and tensor-to-scalar ratio in collapse scheme models, advancing the understanding of gravitational waves in this context.

Findings

First tensor power spectrum calculation in collapse models

Predicted tensor-to-scalar ratio differs from standard inflation

Supports the viability of collapse schemes in explaining gravitational waves

Abstract

The inflationary paradigm is an important cornerstone of the concordance cosmological model. However, standard inflation cannot fully address the transition from an early homogeneous and isotropic stage, to another one lacking such symmetries corresponding to our present universe. In previous works, a self-induced collapse of the wave function has been suggested as the missing ingredient of inflation. Most of the analysis regarding the collapse hypothesis has been solely focused on the characteristics of the spectrum associated to scalar perturbations, and within a semiclassical gravity framework. In this Letter, working in terms of a joint metric-matter quantization for inflation, we calculate, for the first time, the tensor power spectrum and the tensor-to-scalar ratio corresponding to the amplitude of primordial gravitational waves resulting from considering a generic self-induced collapse.