Gravitational to Coulomb force ratio and the origin of the Cosmic magnetic field

Aims: The origin of the seeds of galactic magnetic fields is a subject that remains under debate; here we will explore a new possible mechanism that could provide such seed from charge asymmetries in slowly rotating protogalaxies. Methods: We use current knowledge of galaxy formation and evolution to estimate that a charge imbalance of 1 every ∼10^38± 5 charge carriers in slowly rotating protogalaxies can provide an alternative mechanism to produce such seeds. Results: The gravitationally induced charge imbalance within plasmas in hydrostatic equilibrium lies in the upper range of this estimation, and is higher than possible surviving primordial charge asymmetries. We conclude that this known, but unappreciated thermodynamic property of plasmas in gravitational fields, may have important cosmological consequences.