Very-High-Frequency Gravitational Waves from Multi-Monodromy Inflation

TL;DR

This paper proposes that multi-stage axion monodromy inflation can produce high-frequency gravitational waves with detectable amplitudes, potentially observable by upcoming terrestrial detectors.

Contribution

It introduces a mechanism where interruptions in multi-stage inflation generate observable high-frequency gravitational waves.

Findings

Gravitational wave spikes occur near the end of inflation stages.

Predicted signals are within the sensitivity of future detectors.

Potential for new observational probes of inflation models.

Abstract

We show that in multi-stage axion monodromy inflation an interruption near the end of the penultimate stage can lead to a spike in the gravitational wave background. These gravitational waves are in the frequency range and with an amplitude accessible to proposed terrestrial detectors such as the Einstein Telescope, Cosmic Explorer, and future Levitated Sensor Detector experiments.