Cosmological Magnetic Fields

We discuss the evolution of cosmological magnetic fields from the early universe to the present. We review different scenarios for magnetogenesis in the early universe and follow the subsequent evolution of these fields as the universe recombines. We then focus on the role primordial fields play after recombination in the seeding of stellar and galactic fields and the formation of structure. Cosmological magnetic fields in the intergalactic medium trace the turbulent history of the universe and may contain fossils of the early universe. We conclude by discussing observational probes of cosmological magnetic fields including the study of extragalactic cosmic rays.