Search for Cosmic Strings in the GOODS Survey

TL;DR

This study searches for cosmic strings using Hubble Space Telescope images, finding no evidence and setting upper limits on string properties, which are more stringent than some previous methods but less model-dependent.

Contribution

It introduces a novel search technique for cosmic strings in deep survey images and provides the most stringent limits to date from this method.

Findings

No cosmic strings detected up to certain redshifts.

Sets upper limit on string tension Gμ<3.0x10^{-7}.

Limits are more model-independent than CMB and gravitational wave searches.

Abstract

We search Hubble Space Telescope Treasury Program images collected as part of the Great Observatories Origins Deep Survey for pairs of galaxies consistent with the gravitational lensing signature of a cosmic string. Our technique includes estimates of the efficiency for finding the lensed galaxy pair. In the north (south) survey field we find no evidence out to a redshift of greater than 0.5 (0.3) for cosmic strings to a mass per unit length limit of $G\mu<3.0x10^{-7}$ at 95% confidence limits (C.L.). In the combined 314.9 arcmin$^2$ of the north and south survey fields this corresponds to a global limit on $\Omega_{strings}<0.02$. Our limit on $G\mu$ is more than an order of magnitude lower than searches for individual strings in cosmic microwave background (CMB) data. Our limit is higher than other CMB and gravitational wave searches, however, we note that it is less model dependent than these other searches.