Shafqat Riaz, Theoretical Astrophysics, IAAT — December 09, 2024

Black holes, among the most fascinating predictions of Einstein's theory of General Relativity, are believed to be ubiquitous throughout the Universe. Their immense gravitational pull allows them to accrete surrounding matter, forming an accretion disk and creating what are known as black hole-disk (BH-disk) systems. These systems serve as ideal laboratories for testing theories of gravity in the regime of strong spacetime curvature, where deviations from Einstein's General Relativity are most likely to become evident.

In this talk, I will explore how BH-disk systems can be utilized to test theories of gravity, focusing on reflection spectra from the disk, a technique known as X-ray reflection spectroscopy. Additionally, I will discuss the systematic uncertainties intrinsic to the reflection models widely employed in studying the properties of these systems.