Limiting currents in fermionic conducting cosmic strings

Recently there has been much interest in the possible effects of superconducting cosmic strings. Those effects which are of observational interest involve currents (in units where ℎ = c = 1) of grand unified scale (1015 GeV = 8 x 1020 Amps). We argue that in unified theories conducting strings of the fermionic type cannot achieve such currents because of scattering of current carriers via grand unified interactions. Currents are limited to be six to nine orders of magnitude lower than usually discussed