Gravitational lensing by cosmic strings in the era of wide-field surveys

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≤0.5), we find that observations in a region of size ≈ 1 arc min² will see ∼100 objects, of which ∼5 would be lensed by the string, compared to ∼0.1 lensed by conventional sources.