Duality and scale invariant magnetic fields from bouncing universes

Abstract

Recently, we had numerically shown that, for a non-minimal coupling that is a simple power of the scale factor, scale invariant magnetic fields arise in a class of bouncing universes. In this work, we {\it analytically} evaluate the spectrum of magnetic and electric fields generated in a sub-class of such models. We illustrate that, for cosmological scales which have wavenumbers much smaller than the wavenumber associated with the bounce, the shape of the spectrum is preserved across the bounce. Using the analytic solutions obtained, we also illustrate that the problem of backreaction is severe at the bounce. Finally, we show that the power spectrum of the magnetic field remains invariant under a two parameter family of transformations of the non-minimal coupling function.

v1: 17 pages, 5 figures; v2: 14 pages, 5 figures, bouncing model details and discussion extended, references added, to appear in Phys. Rev. D

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Cited by in corpus (22)

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• Gravitational Waves in Bouncing Cosmologies from Gauge Field Production
• Viable tensor-to-scalar ratio in a symmetric matter bounce
• Effective Theory of Inflationary Magnetogenesis and Constraints on Reheating
• Magnetogenesis in bouncing cosmology
• Inflationary magneto-(non)genesis, increasing kinetic couplings, and the strong coupling problem
• Obviating PBH overproduction for SIGWs generated by Pulsar Timing Arrays in loop corrected EFT of bounce
• Gravitational wave generation in a viable scenario of inflationary magnetogenesis
• Cross-correlations between scalar perturbations and magnetic fields in bouncing universes
• Magnetogenesis in Matter - Ekpyrotic Bouncing Cosmology
• Primordial Magnetogenesis in a Bouncing Universe
• Regularized-Renormalized-Resummed loop corrected power spectrum of non-singular bounce with Primordial Black Hole formation
• Constraining models of Inflationary Magnetogenesis with NANOGrav
• Sourced fluctuations in generic slow contraction
• Sourced Scalar Fluctuations in Bouncing Cosmology
• Negative non-Gaussianity as a salvager for PBHs with PTAs in bounce
• Magnetogenesis in Cyclical Universe
• Hilltop inflation and generation of helical magnetic field
• Smooth magnetogenesis
• Primordial magnetogenesis in a bouncing model with dark energy
• Primordial Magnetic Field from Gravitationally Coupled Electrodynamics in Bouncing Scenario