Femto-lensing due to a Cosmic String

Chul-Moon Yoo, Ryo Saito, Yuuti Sendouda, Ketaro Takahashi, Daisuke Yamauchi

We consider femto-lensing due to a cosmic string. If a cosmic string with the deficit angle Δ ∼ 100 [femto-arcsec] ∼ 10−18 [rad] exists around the line of sight of a gamma-ray burst, we may observe characteristic interference patterns caused by gravitational lensing in the energy spectrum of the gamma-ray burst. This “femto-lensing” event was first proposed as a tool to probe small mass primordial black holes. In this paper, we propose the use of femto-lensing to probe cosmic strings with extremely small tension. Observability conditions and the event rate are discussed. Differences between the cases of a point mass and a cosmic string are presented.

Progress of Theoretical and Experimental Physics 

2013

1

https://doi.org/10.1093/ptep/pts045

1209.0903