Electromagnetic radiation from superconducting string cusps

Cusps in superconducting cosmic strings produce strongly beamed electromagnetic radiation. To calculate the energy emitted requires taking into account the effect of the charge carriers on the string motion, which has previously been done only heuristically. Here, we use the known exact solution to the equations of motion for the case where the current is chiral to update previous calculations for the total energy, spectrum and angular distribution in that case. We analyze the dependence of the radiated energy on the cusp parameters, and discuss which types of cusp dominate the total radiation emitted from an ensemble.