Cosmological Inflation: Theory and Observations

TL;DR

This paper reviews the theory of cosmological inflation, emphasizing its link between quantum physics and large-scale cosmic observations, especially through CMB anisotropies.

Contribution

It provides a comprehensive overview of inflation theory and explains how CMB measurements can test predictions of the inflationary model.

Findings

Quantum fluctuations during inflation lead to observable CMB anisotropies.

CMB temperature and polarization data can probe the physics of the early universe.

Inflationary models predict specific signatures in the CMB that can be tested observationally.

Abstract

In this article we review the theory of cosmological inflation with a particular focus on the beautiful connection it provides between the physics of the very small and observations of the very large. We explain how quantum mechanical fluctuations during the inflationary era become macroscopic density fluctuations which leave distinct imprints in the cosmic microwave background (CMB). We describe the physics of anisotropies in the CMB temperature and polarization and discuss how CMB observations can be used to probe the primordial universe.