Weak reaction freeze-out constraints on primordial magnetic fields

Abstract

We explore constraints on the strength of the primordial magnetic field based upon the weak reaction freeze-out in the early universe. We find that limits on the strength of the magnetic field found in other works are recovered simply by examining the temperature at which the rate of weak reactions drops below the rate of universal expansion (${\Gamma }_w\le$ H). The temperature for which the $n/p$ ratio at freeze-out leads to acceptable helium production implies limits on the magnetic field. This simplifies the application of magnetic fields to other cosmological variants of the standard big-bang. As an illustration we also consider effects of neutrino degeneracy on the allowed limits to the primordial magnetic field.

Submitted to Phys. Rev. D., 6 pages, 2 figures

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• Cosmological Limits on Slightly Skew Stresses
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Cited by in corpus (4)

• Magnetic Fields in the Early Universe
• Updated constraint on a primordial magnetic field during big bang nucleosynthesis and a formulation of field effects
• Effects of power law primordial magnetic field on big bang nucleosynthesis
• The new higher-order generalized uncertainty principle and primordial big bang nucleosynthesis