Gravitational Waves from a Gauge Field Non-minimally Coupled to Gravity
Abstract
An axion-like spectator during inflation can trigger a tachyonic instability which amplifies the modes of one of the helicities of the gauge field, resulting in the production of parity-violating gravitational waves (GWs). In this paper we investigate the impact of the coupling $RFF$ of the gauge field to gravity on the production of GWs. We find that such a coupling introduces a multiplicative factor to the tachyonic mass, which effectively enhances the amplitude of the gauge field modes. Produced GWs are expected to be observed by future space-based GW detectors. Additionally, we find that the strong backreaction due to particle production leads to multiple peaks in the energy spectrum of GWs.
- Publication:
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arXiv e-prints
- Pub Date:
- September 2024
- DOI:
- 10.48550/arXiv.2409.08312
- arXiv:
- arXiv:2409.08312
- Bibcode:
- 2024arXiv240908312H
- Keywords:
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- Astrophysics - Cosmology and Nongalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Phenomenology
- E-Print:
- 8 pages, 3 figures