Astrophysical black hole candidates are thought to be the Kerr black holes of general
relativity, but there is not yet direct observational evidence that the spacetime geometry …

The continuum-fitting and the iron line methods are leading techniques capable of probing
the spacetime geometry around astrophysical black hole candidates and testing the no-hair …

We investigate the null geodesics and the shadow cast by the Kerr–Newman–Kiselev–
Letelier (KNKL) black hole for the equation of state parameter\(\omega _q=-2/3\) and for …

We present the first X-ray reflection model for testing the assumption that the metric of
astrophysical black holes is described by the Kerr solution. We employ the formalism of the …

Einstein's theory of General Relativity predicts that the spacetime metric around
astrophysical black holes is described by the Kerr solution. In this work, we employ state-of …

X-ray reflection spectroscopy is a powerful tool for probing the strong gravity region of black
holes and can be used for testing general relativity in the strong field regime. Simplifications …

We consider the recent datasets of quasiperiodic oscillations from eight different low mass x-
ray binaries. We here interpret their physical features in the context of given regular black …

Recently, two of us have found a family of singularity-free rotating black hole solutions in
Einstein's conformal gravity. These spacetimes are characterized by three parameters: the …

Recently, a family of hairy black holes in 4-dimensional Einstein gravity minimally coupled to
a complex, massive scalar field was discovered [1]. Besides the mass M and spin angular …

The continuum-fitting and the iron-line methods are currently the two leading techniques for
measuring the spins of accreting black holes. In the past few years, these two methods have …