Related papers: Testing General Relativity with X-ray Reflection S…
General Relativity is a hugely successful description of gravitation. However, both theory and observations suggest that General Relativity might have significant classical and quantum corrections in the Strong Gravity regime. Testing the…
Probing gravity in its strongest regime is a central goal of modern physics, as the nature of the most compact objects reflects fundamental aspects of Einstein's theory of general relativity (GR). In GR, black holes are regarded as the most…
Black holes are the sources of the strongest gravitational fields that can be found today in the Universe and are ideal laboratories for testing Einstein's theory of General Relativity in the strong field regime. In this letter, I show that…
X-ray reflection spectroscopy is currently one of the leading techniques for studying the inner part of accretion disks around black holes, measuring black hole spins, and even testing fundamental physics in strong gravitational fields.…
The study of hyperbolic binary black hole encounters yields an effective probe of the strong field regime of black holes, thus providing an additional channel to test General Relativity. We study the scattering of two black holes in…
The detections of gravitational-wave (GW) signals from compact binary coalescence by ground-based detectors have opened up the era of GW astronomy. These observations provide opportunities to test Einstein's general theory of relativity at…
The gravitational wave observations of colliding black holes have opened a new window into the unexplored extreme gravity sector of physics, where the gravitational fields are immensely strong, non-linear, and dynamical. 10 binary black…
Recently, we have extended the X-ray reflection model relxill to test the spacetime metric in the strong gravitational field of astrophysical black holes. In the present Letter, we employ this extended model to analyze XMM-Newton, NuSTAR,…
Accreting black holes are believed to emit X-rays which then mediate information about strong gravity in the vicinity of the emission region. We report on a set of new routines for the Xspec package for analysing X-ray spectra of black-hole…
It is well known that Einstein's General Relativity (GR) achieved a great success and overcame lots of experimental tests. On the other hand, GR also showed some shortcomings and flaws which today advise theorists to ask if it is the…
Accreting black holes often show iron line emission in their X-ray spectra. When this line emission is very broad or variable then it is likely to originate from close to the black hole. The theory and observations of such broad and…
The recent LIGO detection of gravitational waves from black-hole binaries offers the exciting possibility of testing gravitational theories in the previously inaccessible strong-field, highly relativistic regime. While the LIGO detections…
The Einstein Equivalence Principle (EEP) is one of the foundations of the theory of General Relativity and several alternative theories of gravitation predict violations of the EEP. Experimental constraints on this fundamental principle of…
The nature of gravity is fundamental to our understanding of our own solar system, the galaxy and the structure and evolution of the Universe. Einstein's general theory of relativity is the standard model that is used for almost ninety…
The Energetic X-ray Imaging Survey Telescope (EXIST) is under study for the proposed Black Hole Finder Probe, one of the three Einstein Probe missions in NASA's proposed Beyond Einstein Program. EXIST would have unique capabilities: it…
The violent collisions of black holes provide for excellent test-beds of Einstein's general relativity in the strong/dynamical gravity regime. We here demonstrate the resolving power one can gain upon the use of multi-band observations of…
Searches for empirical clues beyond Einstein's general relativity (GR) are crucial to understand gravitation and spacetime. Radio pulsars have been playing an important role in testing gravity theories since 1970s. Because radio timing of…
Active Galactic Nuclei (AGN) are perfect laboratories to check General Relativity (GR) effects by using Broad Line Region (BLR) clouds eclipses to probe the innermost regions of the accretion disk. A new relativistic X-ray spectral model…
Extreme-mass-ratio inspirals consist of binary systems of compact objects, with orders of magnitude differences in their masses, in the regime where the dynamics are driven by gravitational wave emission. The unique nature of…
The non-detection of dark matter (DM) particles in increasingly stringent laboratory searches has encouraged alternative gravity theories where gravity is sourced only from visible matter. Here, we consider whether such theories can pass a…