Galactic magnetic fields from superconducting strings

We use a simple analytic model for the evolution of currents in superconducting strings to estimate the strength of the "seed" magnetic fields generated by these strings. This model is an extension of the string network evolution model of Martins and Shellard depending on a parameter f which characterizes the importance of equilibration processes in the evolution of the currents. For GUT-scale strings or slightly lower energy, we find that a viable seed magnetic field for the galactic dynamo can be generated if the equilibration is weak. On the other hand, electroweak-scale strings create magnetic fields that are smaller than required.