Statistics of the Microwave Background Anisotropies Caused by the Squeezed Cosmological Perturbations

TL;DR

This paper analyzes how quantum-mechanical squeezed states of cosmological perturbations lead to large statistical uncertainties in microwave background anisotropies, complicating the extraction of cosmological information.

Contribution

It derives and quantifies the large variances in temperature correlations caused by squeezed quantum states of perturbations.

Findings

Large theoretical variances in temperature correlations due to squeezing.

Statistical uncertainties hinder precise cosmological measurements.

Quantum origin of perturbations impacts observational data analysis.

Abstract

It is likely that the observed large-angular-scale anisotropies in the microwave background radiation are induced by the cosmological perturbations of quantum-mechanical origin. Such perturbations are now placed in squeezed vacuum quantum states and, hence, are characterized by large variances of their amplitude. The statistical properties of the anisotropies should reflect the underlying statistics of the squeezed vacuum quantum states. The theoretical variances for the temperature angular correlation function are derived and described quantitatively. It is shown that they are indeed large. Unfortunately, these large theoretical statistical uncertainties will make the extraction of cosmological information from the measured anisotropies a much more difficult problem than we wanted it to be.