Universal upper limit on inflation energy scale from cosmic magnetic field

Abstract

Recently observational lower bounds on the strength of cosmic magnetic fields were reported, based on gamma-ray flux from distant blazars. If inflation is responsible for the generation of such magnetic fields then the inflation energy scale is bounded from above as rho_{inf}^{1/4} < 2.5 times 10^{-7}M_{Pl} times (B_{obs}/10^{-15}G)^{-2} in a wide class of inflationary magnetogenesis models, where B_{obs} is the observed strength of cosmic magnetic fields. The tensor-to-scalar ratio is correspondingly constrained as r< 10^{-19} times (B_{obs}/10^{-15}G)^{-8}. Therefore, if the reported strength B_{obs} \geq 10^{-15}G is confirmed and if any signatures of gravitational waves from inflation are detected in the near future, then our result indicates some tensions between inflationary magnetogenesis and observations.

12pages, v2: several discussions and references added, version accepted for publication by JCAP

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• Magnetic fields from inflation?
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Cited by in corpus (19)

• Adding helicity to inflationary magnetogenesis
• Schwinger Effect in 4D de Sitter Space and Constraints on Magnetogenesis in the Early Universe
• Consistent generation of magnetic fields in axion inflation models
• Gamma-ray observations of blazars and the intergalactic magnetic field spectrum
• Early Cosmological Evolution of Primordial Electromagnetic Fields
• A scenario for inflationary magnetogenesis without strong coupling problem
• Magnetic field spectrum at cosmological recombination revisited
• CMB power spectra induced by primordial cross-bispectra between metric perturbations and vector fields
• Generation of large-scale magnetic fields, non-Gaussianity, and primordial gravitational waves in inflationary cosmology
• Generation of large-scale magnetic fields from inflation in teleparallelism
• Stealth magnetic field in de Sitter spacetime
• Gravitational wave trispectrum in the axion-SU(2) model
• Warm inflation in the presence of magnetic fields
• Gradient expansion formalism for magnetogenesis in the kinetic coupling model
• Primordial Helical Magnetic Fields from Inflation?
• Large-scale gauge spectra and pseudoscalar couplings
• Intergalactic medium rotation measure of primordial magnetic fields
• Super-horizon resonant magnetogenesis during inflation
• The hypermagnetic power spectra and the phases of Sakharov oscillations