Cosmological effects of superconducting strings

Superconducting cosmic strings are a plausible consequence of symmetry breaking in grand unified gauge theories. The luminosity in electromagnetic radiation of an oscillating current-carrying loop may substantially exceed the luminosity in gravitational radiation. In the typical case considered, the energy released electromagnetically is 10⁴⁹ erg s^-1, or 10⁶⁶ erg in toto. Several consequences follow from this, the most interesting of which is the possibility that such loops may heat their surroundings, generating large, dense spherical shells of gas. Galaxies forming on these gravitationally unstable shells at moderate redshift will be seen at the present epoch to lie on bubbles having radii in the range 10-20h^-1 Mpc if the initial ratio of luminosity in electromagnetic waves to that in gravitational wavess is > 10^-3 for mass/length 10²² g cm^-1. The required primordial energy density in magnetic fields is > 3 × 10^-9 of the radiation energy density, if the charge carriers are bosons or superheavy fermions. Since these shells fill up space, the galaxies will have a distribution similar to that found in a recent survey of the northern sky. When the current saturates, a loop will emit particles copiously, and may be seen as an X-ray source at z ∼ 10-50. Such loops may also contribute significantly to the hard X-ray and γ-ray backgrounds and to 10²⁰ eV cosmic rays.