In pure axion inflation, detectable gravitational wave signals arise only in parameter regions with strong backreaction that violate the upper bound on ΔN_eff.
Magnetogenesis from axion inflation
7 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary potential and use lattice simulations to calculate the magnetic field strength, helicity and correlation length at the end of inflation. For small values of the axion-gauge field coupling strength the results agree with no-backreaction calculations and estimates found in the literature. For larger couplings the helicity of the magnetic field differs from the no-backreaction estimate and depends strongly on the comoving wavenumber. We estimate the post-inflationary evolution of the magnetic field based on known results for the evolution of helical and non-helical magnetic fields. The magnetic fields produced by axion inflation with large couplings to $U(1)_Y$ can reach $B_{\rm eff} \gtrsim 10^{-16}\, {\rm G}$, exhibiting a field strength $B_{\rm phys} \approx 10^{-13}\, {\rm G}$ and a correlation length $\lambda_{\rm phys}\approx10\, {\rm pc}$. This result is insensitive to the exact value of the coupling, as long as the coupling is large enough to allow for instantaneous preheating. Depending on the assumptions for the physical processes that determine blazar properties, these fields can be found consistent with blazar observations based on the value of $B_{\rm eff}$. Finally, the intensity of the magnetic field for large coupling can be enough to satisfy the requirements for a recently proposed baryogenesis mechanism, which utilizes the chiral anomaly of the Standard Model.
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Lattice simulations show that Schwinger currents saturate gauge-field production in axion inflation, yielding universal conductivity and magnetic-field values at the onset of strong backreaction.
Constant electric fields in de Sitter require a tachyonic photon mass ~H, yielding finite positive Schwinger currents for massless fermions and scalars after on-shell renormalization.
Axion-like particles in the trapped misalignment mechanism produce observable gravitational waves while generating intergalactic magnetic fields that exceed blazar lower bounds in the parameter space promising for gravitational wave detection.
Inflationary magnetic fields induce curvature perturbations that form ultralight PBHs, generating a stochastic GW background with model-specific features.
Finite conductivity of the plasma suppresses parametric resonance amplification of electromagnetic fields from ultralight pseudoscalar dark matter, making it impossible to generate magnetic fields of sufficient strength in cosmic voids for observationally viable couplings.
Lecture notes providing a generic introduction to reheating after inflation, covering its theoretical, phenomenological, and observational aspects.
citing papers explorer
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Gravitational waves from axion inflation in the gradient expansion formalism. Part I. Pure axion inflation
In pure axion inflation, detectable gravitational wave signals arise only in parameter regions with strong backreaction that violate the upper bound on ΔN_eff.
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Schwinger effect in axion inflation on a lattice
Lattice simulations show that Schwinger currents saturate gauge-field production in axion inflation, yielding universal conductivity and magnetic-field values at the onset of strong backreaction.
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Classical constant electric fields and the Schwinger effect in de Sitter
Constant electric fields in de Sitter require a tachyonic photon mass ~H, yielding finite positive Schwinger currents for massless fermions and scalars after on-shell renormalization.
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Audible Axion Magnetogenesis: Linking Intergalactic Magnetic Fields and Gravitational Waves
Axion-like particles in the trapped misalignment mechanism produce observable gravitational waves while generating intergalactic magnetic fields that exceed blazar lower bounds in the parameter space promising for gravitational wave detection.
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The Magnetic Origin of Primordial Black Holes: Ultralight PBHs and Secondary GWs
Inflationary magnetic fields induce curvature perturbations that form ultralight PBHs, generating a stochastic GW background with model-specific features.
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Suppressed Magnetogenesis from Ultralight Dark Matter due to Finite Conductivity
Finite conductivity of the plasma suppresses parametric resonance amplification of electromagnetic fields from ultralight pseudoscalar dark matter, making it impossible to generate magnetic fields of sufficient strength in cosmic voids for observationally viable couplings.
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Lectures on Reheating after Inflation
Lecture notes providing a generic introduction to reheating after inflation, covering its theoretical, phenomenological, and observational aspects.