A flashing beacon in axion inflation: recurring bursts of gravitational waves in the strong backreaction regime

• DOI: 10.48550/arxiv.2303.13425
• Publication Date: 2023-01-01
• Authors: J. García-Bellido; Alexandros Papage...; Marco Peloso; Lorenzo Sorbo
• Keywords: High Energy Physics - Phenomenology; Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); axions; gravitational waves / sources; inflation; physics of the early universe;; 0103 physical sciences; FOS: Physical sciences; 01 natural sciences; Astrophysics - Cosmology and Nongalactic Astrophysics

The coupling between a pseudo-scalar inflaton and gauge field leads to an amount of additional density perturbations gravitational waves (GWs) that is strongly sensitive the speed. This naturally results in enhanced GWs at (relatively) small scales exited horizon well after CMB ones, can be probed by variety GW observatories (from pulsar timing arrays, astrometry, space-borne ground-based interferometers). production occurs regime which significantly backreacts on motion. Contrary earlier assumptions, it has been recently shown this characterized oscillatory behavior speed, with period of~${\rm O } \left( 5 \right)$ e-folds. Bursts are produced maxima imprinting nearly periodic bumps frequency-dependent spectrum during inflation. potentially generate correlated peaks appearing same or different experiments.