Generation of magnetic fields in the early Universe

Nonlinear interactions between intense photon and neutrino beams and relativistically hot electron-positron-ion plasmas of the early Universe are considered. It is shown that a small fraction of ions produces large space charge electric fields in the presence of the plasma pressure gradient, relativistic photon ponderomotive force and weak nuclear driving force of neutrinos. Large space charge electric fields can separate pairs, generating the currents which are required for creating magnetic fields in plasmas. The present theory thus offers a possible clue to the origin of primordial magnetic fields in the early Universe. (C) 2003 Elsevier Science B.V. All rights reserved.