Exploring Physics in the Early Universe through the Intergalactic Void Magnetic Fields

Abstract

Recent observations of TeV blazars by Fermi identified deficits of secondary GeV cascade photons. These observations can be explained by intergalactic void magnetic fields, which may have a primordial origin. If the magnetic fields are helical and generated in the early Universe such as before the electroweak symmetry breaking, nontrivial interaction between (hyper) magnetic fields and other particles can cause some interesting and non negligible phenomena. In this article, it is shown that the baryon asymmetry can be generated by the chiral anomaly, and baryon asymmetry is not completely washed out by the electroweak sphalerons. Thus, this mechanism can be responsible for the present baryon asymmetry of the Universe. If this mechanism is responsible for the present Universe, the physics beyond the Standard Model of particle physics is needed for the generation of (hyper) magnetic fields but not for the baryogenesis. As mechanisms of magnetogenesis suitable for this baryogenesis, pseudoscalar inflation and chiral plasma instability are discussed.