The History of Inflation from Microwave Background Polarimetry and Laser Interferometry

TL;DR

This paper explores how combining microwave background polarization measurements with space-based laser interferometry can significantly constrain the inflationary history of the early universe by detecting gravitational waves.

Contribution

It demonstrates, through Monte Carlo simulations, that joint measurements can tightly constrain inflation models and the underlying physical mechanisms.

Findings

Joint measurements can constrain inflationary parameters

Laser interferometry and microwave polarization are complementary

Inflation models can be distinguished with combined data

Abstract

A period of inflation in the early universe produces a nearly scale-invariant spectrum of gravitational waves over a huge range in wavelength. If the amplitude of this gravitational wave background is large enough to be detectable with microwave background polarization measurements, it will also be detectable directly with a space-based laser interferometer. Using a Monte Carlo sampling of inflation models, we demonstrate that the combination of these two measurements will strongly constrain the expansion history during inflation and the physical mechanism driving it.