We study gravitational lensing by the Gibbons-Maeda-Garfinkle-Horowitz-Strominger (GMGHS) charged black hole of heterotic string theory and obtain the angular position and magnification of the relativistic images. Modeling the supermassive central object of the galaxy as a GMGHS black hole, we estimate the numerical values of different strong-lensing parameters. We find that there is no significant string effect present in the lensing observables in the strong-gravity scenario.
@article{arxiv.gr-qc/0306016,
title = {Gravitational lensing by a charged black hole of string theory},
author = {A. Bhadra},
journal= {arXiv preprint arXiv:gr-qc/0306016},
year = {2009}
}