Motivated by the recent claim for gravitational lensing by a cosmic string, we reinvestigate the probability of finding such an event with upcoming wide-field surveys. If an observed lensing event is suspected to be due to a string, observations of the vicinity of the event in a circle of diameter L centered on the observed lens should reveal several additional lensing events. For a string located nearby $(z\lesssim 0.5),$ we find that observations in a region of size $\approx 1{\mathrm{arc}\mathrm{}\min }^2$ will see $\sim 100$ objects, of which $\sim 5$ would be lensed by the string, compared to $\sim 0.1$ lensed by conventional sources.

• Received 7 May 2003

DOI:https://doi.org/10.1103/PhysRevD.68.041301