204 citations · 1.8k across the 55 of their papers we have counts for
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Testing General Relativity with NuSTAR data of Galactic Black Holes
Ashutosh Tripathi, Yuexin Zhang, Askar B. Abdikamalov +5
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-the-…
Reflection spectra of accretion disks illuminated by disk-like coronae
Shafqat Riaz, Askar B. Abdikamalov, Dimitry Ayzenberg +3
Relativistic reflection features in the X-ray spectra of black hole binaries and AGNs are thought to be produced through illumination of a cold accretion disk by a hot corona. In t…
Testing the Kerr Black Hole Hypothesis with GX 339-4 by a combined analysis of its thermal spectrum and reflection features
Ashutosh Tripathi, Askar B. Abdikamalov, Dimitry Ayzenberg +3
We analyze simultaneous observations with NuSTAR and Swift of the black hole binary GX 339-4 in which we clearly detect both a strong thermal component and prominent relativistic r…
Testing the Keplerian disk hypothesis using X-ray reflection spectroscopy
Ashutosh Tripathi, Biao Zhou, Askar B. Abdikamalov +3
The Novikov-Thorne model is the standard framework for the description of geometrically thin and optically thick accretion disks around black holes and is widely used to study the…
Impact of the returning radiation on the analysis of the reflection spectra of black holes
Shafqat Riaz, Michal Szanecki, Andrzej Niedzwiecki +2
A fraction of the electromagnetic radiation emitted from the surface of a geometrically thin and optically thick accretion disk of a black hole returns to the disk because of the s…
Shining X-rays on asymptotically safe quantum gravity
Biao Zhou, Askar B. Abdikamalov, Dimitry Ayzenberg +3
Asymptotically safe quantum gravity is a promising candidate scenario to provide a UV extension for the effective quantum field theory of Einstein's gravity. The theory has its fou…
X-ray reflection spectroscopy with Kaluza-Klein black holes
Jiachen Zhu, Askar B. Abdikamalov, Dimitry Ayzenberg +6
Kaluza-Klein theory is a popular alternative theory of gravity, with both non-rotating and rotating black hole solutions known. This allows for the possibility that the theory coul…
Reflection features in the X-ray spectrum of Fairall 9 and implications for tests of general relativity
Honghui Liu, Haiyang Wang, Askar B. Abdikamalov +2
X-ray reflection spectroscopy is potentially a powerful tool to probe the spacetime geometry around astrophysical black holes and test general relativity in the strong field regime…
Singularity-free black holes in conformal gravity: new observational constraints
Menglei Zhou, Askar B. Abdikamalov, Dimitry Ayzenberg +4
We consider the family of singularity-free rotating black hole solutions in Einstein's conformal gravity found in Bambi, Modesto & Rachwal (2017) and we constrain the value of the…
Testing general relativity with the stellar-mass black hole in LMC X-1 using the continuum-fitting method
Ashutosh Tripathi, Menglei Zhou, Askar B. Abdikamalov +6
The iron line and the continuum-fitting methods are currently the two leading techniques for measuring black hole spins with electromagnetic radiation. They can be naturally extend…