2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/11426The observed galactic magnetic fields may have a primordial origin. I briefly review the observations, their interpretation in terms of the dynamo theory, and the current limits on cosmological magnetic fields. Several possible mechanisms for generating a primordial magnetic field are then discussed. Turbulence and the evolution of the microscopic fields to macroscopic fields is described in terms of a shell model, which provides an approximation to the full magnetohydrodynamics and indicates the existence of an inverse cascade of magnetic energy. Cosmological seed fields roughly of the order of $10^{-20}$ G at the scale of protogalaxy, as required by the dynamo explanation of galactic magnetic fields, seem rather plausible.19 pages LaTeX, 5 ps-figures, uses sprocl.sty; Invited Talk at the Strong and Electroweak Matter '97, HungaryAstrophysicsHigh Energy Physics - Phenomenologytext