Primordial magnetic fields from inflation?
نویسنده
چکیده
The hot plasma above the electroweak scale contains (hyper) charged scalar particles which are coupled to Abelian gauge fields. Scalars may interact with gravity in a non-conformally invariant way and thus their fluctuations can be amplified during inflation. These fluctuations lead to creation of electric currents and produce inhomogeneous distribution of charge density, resulting in the generation of cosmological magnetic fields. We address the question whether these fields can be coherent at large scales so that they may seed the galactic magnetic fields. Depending upon the mass of the charged scalar and upon various cosmological (critical fraction of energy density in matter, Hubble constant) and particle physics parameters we found that the magnetic fields generated in this way are much larger than vacuum fluctuations. However, their amplitude on cosmological distances is found to be too small for seeding the galactic magnetic fields. Preprint Number: UNIL-IPT-00-09, April 2000 ∗Electronic address: [email protected] †Electronic address : [email protected]
منابع مشابه
Primordial magnetic fields from pseudo Goldstone bosons.
The existence of large-scale magnetic fields in galaxies is well established, but there is no accepted mechanism for generating a primordial field which could grow into what is observed today. We discuss a model which attempts to account for the necessary primordial field by invoking a pseudo-Goldstone boson coupled to electromagnetism. The evolution of this boson during inflation generates a m...
متن کاملOn the Magnetic Evolution in Friedmann Universes and the Question of Cosmic Magnetogenesis
We analyse the evolution of primordial magnetic fields in spatially flat Friedmann universes and reconsider the belief that, after inflation, these fields decay adiabatically on all scales. Without abandoning classical electromagnetism or standard cosmology, we demonstrate that this is not necessarily the case for superhorizon-sized magnetic fields. The underlying reason for this is causality, ...
متن کاملThe charged inflaton and its gauge fields: Preheating and initial conditions for reheating
We calculate particle production during inflation and in the early stages of reheating after inflation in models with a charged scalar field coupled to Abelian and non-Abelian gauge fields. A detailed analysis of the power spectra of primordial electric fields, magnetic fields and charge fluctuations at the end of inflation and preheating is provided. We carefully account for the Gauss constrai...
متن کاملPrimordial magnetic fields and nonlinear electrodynamics
The creation of large scale magnetic fields is studied in an inflationary universe where electrodynamics is assumed to be nonlinear. After inflation ends electrodynamics becomes linear and thus the description of reheating and the subsequent radiation dominated stage are unaltered. The nonlinear regime of electrodynamics is described by lagrangians having a power law dependence on one of the in...
متن کاملN-flationary magnetic fields
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...
متن کاملLarge-Scale Primordial Magnetic Fields from Inflation and Preheating
We consider models in which the (transverse) photon mass is non-zero during inflation and drops to zero non-adiabatically at the end of inflation. Through this process, vacuum fluctuations of the photon field are converted into physical, longwavelength modes with high amplitude. The resulting spectrum of the field strength is approximately Bl ∼ l, where l is the relevant coherence scale. With a...
متن کامل