Speaker
Description
We show that in some ranges of the charge parameters charged stringy black hole metric can provide the same ISCO as in the case of the well known Kerr metric for the test particles. Based on the idea that charge parameters of the stringy black hole metric can provide the same ISCO for the test particles it would be difficult to distinguish these two metrics if one relies on the observations that have a strong dependence on the ISCO radius. So, based on this idea we show that in the case of electrically charged stringy black hole the charge parameter can completely mimic the rotation parameter of the Kerr metric; black hole with magnetic charge can mimic the spin up to $a=0.85$ for magnetic dipoles endowed with a magnetic dipole moment; and up to $a=0.8$ for magnetic monopoles.