CMB Distortions from Superconducting Cosmic Strings

TL;DR

This paper investigates how electromagnetic radiation from superconducting cosmic strings could distort the CMB spectrum, deriving constraints on string properties from current and future observations.

Contribution

It provides new constraints on superconducting cosmic string tension and currents based on CMB distortion data from COBE-FIRAS and PIXIE.

Findings

PIXIE will significantly tighten constraints on string tension and current.

Absence of CMB distortions limits string tension to G mu_s < 10^{-18}.

Weak currents I < 10 TeV remain viable.

Abstract

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