Cosmological constraints on non-standard inflationary quantum collapse models

TL;DR

This paper explores how quantum-gravity induced collapse models can explain cosmic structure formation, leading to deviations in the primordial spectrum and testing these models against recent CMB and galaxy survey data.

Contribution

It introduces and tests non-standard inflationary collapse models inspired by Penrose and Diáosi, providing observational constraints on their parameters.

Findings

Several collapse models are compatible with current CMB and LRG data.

The models predict deviations from the scale-invariant spectrum.

No constraints on the collapse timescale were found.

Abstract

We briefly review an important shortcoming --unearthed in previous works-- of the standard version of the inflationary model for the emergence of the seeds of cosmic structure. We consider here some consequences emerging from a proposal inspired on ideas of Penrose and Di\'osi about a quantum-gravity induced reduction of the wave function, which has been put forward to address the shortcomings, arguing that its effect on the inflaton field is what can lead to the emergence of the seeds of cosmic structure. The proposal leads to a deviation of the primordial spectrum from the scale-invariant Harrison-Zel'dovich one, and consequently, to a different CMB power spectrum. We perform statistical analyses to test two quantum collapse schemes with recent data from the CMB, including the 7-yr release of WMAP and the matter power spectrum measured using LRGs by the Sloan Digital Sky Survey. Results from the statistical analyses indicate that several collapse models are compatible with CMB and LRG data, and establish constraints on the free parameters of the models. The data put no restriction on the timescale for the collapse of the scalar field modes.