Alleviation of anomalies from the non-oscillatory vacuum in loop quantum cosmology

TL;DR

This paper explores how a non-oscillatory vacuum in Loop Quantum Cosmology can produce a primordial power spectrum with infrared suppression, potentially alleviating certain anomalies in cosmic microwave background observations.

Contribution

It introduces a model with exponential infrared suppression in the primordial spectrum, analyzed through Bayesian methods against CMB data, showing observational preferences and anomaly alleviation.

Findings

Preference for suppression scale within observable window

Model slightly affects parity anomaly

Capable of alleviating lensing and power suppression anomalies

Abstract

In this work we investigate observational signatures of a primordial power spectrum with exponential infrared suppression, motivated by the choice of a non-oscillatory vacuum in a bouncing and inflationary geometry within Loop Quantum Cosmology (LQC). We leave the parameter that defines the scale at which suppression occurs free and perform a Bayesian analysis, comparing with CMB data. The data shows a preference for some of the suppression to be within the observable window. Guided by this analysis, we choose concrete illustrative values for this parameter. We show that the model affects only slightly the parity anomaly, but it is capable of alleviating the lensing and power suppression anomalies.