Can the Gravitational Wave Background from Inflation be Detected Locally?

TL;DR

This paper explores the potential for detecting the gravitational wave background from inflation locally, revealing that larger inflationary signals in cosmic microwave background anisotropies imply smaller local gravitational wave signals, challenging detection expectations.

Contribution

It demonstrates that local detection of inflationary gravitational waves is unlikely if the cosmic microwave background anisotropies are dominated by such waves, based on minimal inflation physics assumptions.

Findings

LIGO is unlikely to detect inflationary gravitational waves.

Detection may be possible with beam-in-space detectors.

Larger COBE signals imply smaller local gravitational wave signals.

Abstract

The Cosmic Background Explorer (COBE) detection of microwave background anisotropies may contain a component due to gravitational waves generated by inflation. It is shown that the gravitational waves from inflation might be seen using `beam-in-space' detectors, but not the Laser Interferometer Gravity Wave Observatory (LIGO). The central conclusion, dependent only on weak assumptions regarding the physics of inflation, is a surprising one. The larger the component of the COBE signal due to gravitational waves, the {\em smaller} the expected local gravitational wave signal.