CMB distortions from superconducting cosmic strings

Abstract

We reconsider the effect of electromagnetic radiation from superconducting strings on cosmic microwave background $\ensuremath{\mu}$ and $y$ distortions and derive present (COBE-FIRAS) and future (PIXIE) constraints on the string tension, ${\ensuremath{\mu}}_{s}$, and electric current, $I$. We show that absence of distortions of the cosmic microwave background in PIXIE will impose strong constraints on ${\ensuremath{\mu}}_{s}$ and $I$, leaving the possibility of light strings ($G{\ensuremath{\mu}}_{s}\ensuremath{\lesssim}{10}^{\ensuremath{-}18}$) or relatively weak currents ($I\ensuremath{\lesssim}10\text{ }\text{ }\mathrm{TeV}$).