Search for Cosmic Strings in the GOODS Survey
  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. 
J.L. Christiansen, E. Albin, K.A. James, J. Goldman, D. Maruyama, G.F.   Smoot