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arXiv · 2409.08312

Gravitational Waves from a Gauge Field Non-minimally Coupled to Gravity

Jian-Feng He·Chengjie Fu·Kai-Ge Zhang·Zong-Kuan Guo
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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.

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Jian-Feng He, Chengjie Fu, Kai-Ge Zhang, Zong-Kuan Guo. 2024-09-12. Gravitational Waves from a Gauge Field Non-minimally Coupled to Gravity. https://doi.org/10.1103/physrevd.111.023536

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