2002/11/02 by D. Boyanovsky, H. J. de Vega, M. Simionato
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Geomagnetism and Paleomagnetism Studies #Solar and Space Plasma Dynamics #astro-ph #hep-ph
paper · pdf · doi:10.1103/physrevd.67.123505
published as Phys.Rev. D67 (2003) 123505 · LaTex, 25 pages, no figures, to appear in Phys. Rev. D
openalex publication_date 2002/11/02 · arxiv created 2003/04/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the generation of large scale primordial magnetic fields by a cosmological phase transition during the radiation dominated era. The setting is a theory of N charged scalar fields coupled to an abelian gauge field, that undergoes a phase transition at a critical temperature much larger than the electroweak scale. The dynamics after the transition features two distinct stages: a spinodal regime dominated by linear long-wavelength instabilities, and a scaling stage in which the non-linearities and backreaction of the scalar fields are dominant. This second stage describes the growth of horizon sized domains. We implement a recently introduced formulation to obtain the spectrum of magnetic fields that includes the dissipative effects of the plasma. We find that large scale magnetogenesis is very efficient during the scaling regime. The ratio between the energy density on scales larger than L and that in the background radiation r(L,T) = rhoB(L,T)/rhocmb(T) is r(L,T) \∼ 10-34 at the Electroweak scale and r(L,T) \∼ 10-14 at the QCD scale for L \∼ 1 Mpc. The resulting spectrum is insensitive to the magnetic diffusion length. We conjecture that a similar mechanism could be operative after the QCD chiral phase transition.