Gravitational Waves from an Axion-Dark Photon System: A Lattice Study

Abstract

In this work, we present a lattice study of an axion - dark photon system in the early Universe and show that the stochastic gravitational wave (GW) background produced by this system may be probed by future GW experiments across a vast range of frequencies. The numerical simulation on the lattice allows us to take into account non-linear backreaction effects and enables us to accurately predict the final relic abundance of the axion or axion-like particle (ALP) as well as its inhomogeneities, and gives a more precise prediction of the GW spectrum. Importantly, we find that the GW spectrum has more power at high momenta due to $2\to 1$ processes. Furthermore, we find the degree of polarization of the peak of the GW spectrum depends on the ALP-dark photon coupling and that the polarization can be washed out or even flipped for large values thereof. In line with recent results in the literature, we find the ALP relic abundance may be suppressed by two orders of magnitude and discuss possible extensions of the model that expand the viable parameter space. Finally, we discuss the possibility to probe ultralight ALP dark matter via spectral distortions of the CMB.

27 pages, 9 figures. The source material includes the GW spectra in tabulated form. Version submitted for publication

References in corpus (12)

• Ultralight scalars as cosmological dark matter
• Monodromy in the CMB: Gravity Waves and String Inflation
• A Natural Framework for Chaotic Inflation
• The Powers of Monodromy
• F-term Axion Monodromy Inflation
• Gravitational Waves from Abelian Gauge Fields and Cosmic Strings at Preheating
• D7-Brane Chaotic Inflation
• Towards Universal Axion Inflation and Reheating in String Theory
• Where in the String Landscape is Quintessence
• Chirality of the gravitational-wave background and pulsar-timing arrays
• Testing clockwork axion with gravitational waves
• Natural Milli-Charged Inflation

Cited by in corpus (17)

• Dark photon limits: a handbook
• Primordial gravitational waves in the nano-Hertz regime and PTA data -- towards solving the GW inverse problem
• Cosmological Background Interpretation of Pulsar Timing Array Data
• Gravitational Waves and Dark Photon Dark Matter from Axion Rotations
• Gravitational wave background from non-Abelian reheating after axion-like inflation
• Challenges and Opportunities of Gravitational Wave Searches above 10 kHz
• Audible Axions with a Booster: Stochastic Gravitational Waves from Rotating ALPs
• One $\mu$ to rule them all: CMB spectral distortions can probe domain walls, cosmic strings and low scale phase transitions
• Dark photon dark matter from an oscillating dilaton
• Gravitational Wave Echo of Relaxion Trapping
• Axion dark matter from frictional misalignment
• Resonant production of dark photons from axion without a large coupling
• Fast Likelihood-free Reconstruction of Gravitational Wave Backgrounds
• Present and future of CosmoLattice
• B-modes from Post-inflationary Gravitational Waves Sourced by Axionic Instabilities at Cosmic Reionization
• Supercooled Audible Axions
• Axion Fragmentation on the Lattice