Gravitational Waves sourced by Gauge Fields during Inflation
arXiv:2510.00869 · doi:10.1088/1475-7516/2026/03/043
Abstract
We study the inflationary gravitational wave background induced by Abelian gauge fields generated by non-minimal kinetic and axial couplings to the inflaton. We show that, up to slow-roll corrections, for coupling functions that share the same dependence on conformal time, the gravitational wave spectrum is nearly scale invariant. We also derive its amplitude for generic gauge field coupling parameters, within the slow-roll approximation. The coupling values and the scale of inflation for which the induced gravitational wave background is observable, while ensuring that back-reaction on the inflationary dynamics remains negligible, are calculated. We find that a sizeable axial coupling can boost this secondary gravitational wave signal above the standard inflationary background. In the course of our analysis, we also show how to analytically match tensor perturbations across an arbitrary number of eras with different equations of state.
41 pages, 9 figures
References in corpus (35)
- Evidence for strong extragalactic magnetic fields from Fermi observations of TeV blazars
- Cosmological Backgrounds of Gravitational Waves
- Cosmological Magnetic Fields: Their Generation, Evolution and Observation
- Magnetic fields of non-degenerate stars
- The origin, evolution and signatures of primordial magnetic fields
- Inflationary Universe with Anisotropic Hair
- Gauge Fields and Inflation
- Strong magnetic fields in normal galaxies at high redshifts
- Generation of Large-Scale Magnetic Fields in Single-Field Inflation
- Magnetic fields from inflation?
- Chromo-Natural Inflation: Natural inflation on a steep potential with classical non-Abelian gauge fields
- Parity violation in the Cosmic Microwave Background from a pseudoscalar inflaton
- Phenomenology of a Pseudo-Scalar Inflaton: Naturally Large Nongaussianity
- Primordial Magnetic Fields and Causality
- Nonhelical inverse transfer of a decaying turbulent magnetic field
- Adding helicity to inflationary magnetogenesis
- Magnetic fields in the early universe
- The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode
- Can slow roll inflation induce relevant helical magnetic fields?
- Progress on Cosmological Magnetic Fields
- Discovery of Magnetic Fields Along Stacked Cosmic Filaments as Revealed by Radio and X-Ray Emission
- Evolution of Magnetic Fields in Freely Decaying Magnetohydrodynamic Turbulence
- The turbulent chiral-magnetic cascade in the early universe
- The Cosmic Large-Scale Structure in X-rays (CLASSIX) Cluster Survey I: Probing galaxy cluster magnetic fields with line of sight rotation measures
- Can the observed large scale magnetic fields be seeded by helical primordial fields?
- Scale-invariant Helical Magnetic Fields from Inflation
- Backreaction from gauge fields produced during inflation
- The detection of cluster magnetic fields via radio source depolarisation
- Scale-invariant helical magnetic field evolution and the duration of inflation
- Magnetogenesis in Higgs-Starobinsky inflation
- The non-linear dynamics of axion inflation: a detailed lattice study
- The LOFAR View of Cosmic Magnetism
- On the nature of LOFAR RMs and new constraints on magnetic fields in cosmic filaments and on magnetogenesis scenarios
- Gradient expansion formalism for magnetogenesis in the kinetic coupling model
- Probing Reheating Phase via Non-Helical Magnetogenesis and Secondary Gravitational Waves