N-flationary magnetic fields

Abstract

There is increasing interest in the role played by pseudo Nambu-Goldstone bosons (pNGBs) in the construction of string-inspired models of inflation. In these models the inflaton is expected to be coupled to gauge fields, and will lead to the generation of magnetic fields that can be of cosmological interest. We study the production of such fields mainly focusing on the model of N-flation, where the collective effect of several pNGBs drives inflation. Because the produced fields are maximally helical, inverse cascade processes in the primordial plasma increase significantly their coherence length. We discuss under what conditions inflation driven by pNGBs can account for the observed cosmological magnetic fields. A constraint on the parameters of this class of inflationary scenarios is also derived by requiring that the magnetic field does not backreact on the inflating background.

13pages, minor corrections, references added, final version to be published in JCAP

References in corpus (2)

• Nflation: multi-field inflationary dynamics and perturbations
• Natural Inflation: the status after WMAP 3-year data

Cited by in corpus (11)

• Cosmic Microwave Background Quadrupole and Ellipsoidal Universe
• Large-scale magnetic fields in the inflationary universe
• Rotation of Linear Polarization Plane and Circular Polarization from Cosmological Pseudoscalar Fields
• A Model of Universe Anisotropization
• Inflation-Produced Magnetic Fields in Nonlinear Electrodynamics
• Inflation-Produced Magnetic Fields in R^n F^2 and I F^2 models
• Can the observed large scale magnetic fields be seeded by helical primordial fields?
• Primordial magnetic fields and nonlinear electrodynamics
• Large-scale magnetic fields from inflation due to Chern-Simons-like effective interaction
• The interrelation between the generation of large-scale electric fields and that of large-scale magnetic fields during inflation
• Property of the spectrum of large-scale magnetic fields from inflation