scholarly journals Plasma-photon interaction in curved spacetime: Formalism and quasibound states around nonspinning black holes

2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Enrico Cannizzaro ◽  
Andrea Caputo ◽  
Laura Sberna ◽  
Paolo Pani
Keyword(s):  
Black Holes ◽  
Curved Spacetime ◽  
Photon Interaction

3. Characterizing black holes

2015 ◽  
Author(s):  
Katherine Blundell
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Gravitational Field ◽  
Curved Spacetime ◽  
Remarkable Feature ◽  
Static Limit ◽  
Frame Dragging ◽  
Axis Of Rotation ◽  
Different Types

‘Characterizing black holes’ describes the two different types of black holes: Schwarzschild black holes that do not rotate and Kerr black holes that do. The only distinguishing characteristics of black holes are their mass and their spin. A remarkable feature of a spinning black hole is that the gravitational field pulls objects around the black hole’s axis of rotation, not merely in towards its centre—an effect called frame dragging. The static limit and ergosphere regions of black holes are also described. Einstein’s equations of General Relativity allow many different solutions describing alternative versions of curved spacetime. Could white holes and worm holes exist in our universe?

scholarly journals Decolimation of a jet due to spacetime curvature

1986 ◽  
Vol 119 ◽  
pp. 413-414
Author(s):  
R.C. Kapoor
Keyword(s):  
Black Holes ◽  
Fast Moving ◽  
Particle Density ◽  
Supermassive Black Holes ◽  
Radio Sources ◽  
Curved Spacetime ◽  
Particle Trajectories ◽  
Central Engine ◽  
Spacetime Curvature ◽  
Moving Plasma

Central cores of compact radio sources are believed to contain supermassive black holes accreting material from their vicinity which produce fast moving plasma in the form of directed beams (jets), with apparent opening angles ≥5° (Rees et al. 1981). In case, the jets are produced and their collimation is established on scales few times the SchwarzschiId radius (2m; m=GM/c2) of the central engine, deflection in particle trajectories in the curved spacetime () would be large enough to widen the beam and thereby reduce the particle density and effective luminosity in the beam (Fig.1).

scholarly journals Acoustic black holes in curved spacetime and the emergence of analogue Minkowski spacetime

2019 ◽  
Vol 99 (10) ◽  
Author(s):  
Xian-Hui Ge ◽  
Mikio Nakahara ◽  
Sang-Jin Sin ◽  
Yu Tian ◽  
Shao-Feng Wu
Keyword(s):  
Black Holes ◽  
Minkowski Spacetime ◽  
Curved Spacetime ◽  
Acoustic Black Holes

scholarly journals The vecro hypothesis

2020 ◽  
Vol 29 (15) ◽  
pp. 2030009
Author(s):  
Samir D. Mathur
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Quantum Gravity ◽  
Black Hole Horizon ◽  
Cosmological Horizon ◽  
Leading Order ◽  
Vacuum Fluctuations ◽  
Curved Spacetime ◽  
Black Hole Information

We consider three fundamental issues in quantum gravity: (a) the black hole information paradox (b) the unboundedness of entropy that can be stored inside a black hole horizon (c) the relation between the black hole horizon and the cosmological horizon. With help from the small corrections theorem, we convert each of these issues into a sharp conflict. We then argue that all three conflicts can be resolved by the following hypothesis: the vacuum wave functional of quantum gravity contains a “vecro” component made of virtual fluctuations of configurations of the same type that arise in the fuzzball structure of black hole microstates. Further, if we assume that causality holds to leading order in gently curved spacetime, then we must have such a vecro component in order to resolve the above conflicts. The term vecro stands for “Virtual Extended Compression-Resistant Object”, and characterizes the nature of the vacuum fluctuations that resolve the puzzles. It is interesting that puzzle (c) may relate the role of quantum gravity in black holes to observations in the sky.

scholarly journals The refractive index of curved spacetime II: QED, Penrose limits and black holes

2009 ◽  
Vol 2009 (08) ◽  
pp. 089-089 ◽  
Author(s):  
Timothy J Hollowood ◽  
Graham M Shore ◽  
Ross J Stanley
Keyword(s):  
Black Holes ◽  
Refractive Index ◽  
Curved Spacetime

scholarly journals Plasma-photon interaction in curved spacetime. II. Collisions, thermal corrections, and superradiant instabilities

2021 ◽  
Vol 104 (10) ◽  
Author(s):  
Enrico Cannizzaro ◽  
Andrea Caputo ◽  
Laura Sberna ◽  
Paolo Pani
Keyword(s):  
Curved Spacetime ◽  
Photon Interaction

scholarly journals RAPTOR

2020 ◽  
Vol 641 ◽  
pp. A126
Author(s):  
T. Bronzwaer ◽  
Z. Younsi ◽  
J. Davelaar ◽  
H. Falcke
Keyword(s):  
Black Holes ◽  
Radiative Transfer ◽  
Formal Analysis ◽  
Field Configuration ◽  
Stokes Parameters ◽  
Integration Scheme ◽  
Test Problems ◽  
Curved Spacetime ◽  
Invariant Representation ◽  
Accretion Flows

Context. Accreting supermassive black holes are sources of polarized radiation that propagates through highly curved spacetime before reaching the observer. Accurate and efficient numerical schemes for polarized radiative transfer in curved spacetime are needed to help interpret observations of such polarized emission. Aims. We aim to extend our publicly available radiative transfer code RAPTOR to include polarized radiative transfer, so that it can produce simulated polarized observations of accreting black holes. The RAPTOR code must remain compatible with arbitrary spacetimes and it must be efficient in operation, despite the added complexity of polarized radiative transfer. Methods. We provide a brief review of various codes and methods for covariant polarized radiative transfer available in the literature and existing codes, and we present an efficient new scheme. For the spacetime propagation aspect of the computation, we developed a compact, Lorentz-invariant representation of a polarized ray. For the plasma-propagation aspect of the computation, we performed a formal analysis of the stiffness of the polarized radiative-transfer equation with respect to our explicit integrator. We also developed a hybrid integration scheme that switches to an implicit integrator in case of stiffness in order to solve the equation with optimal speed and accuracy for all possible values of the local optical/Faraday thickness of the plasma. Results. We performed a comprehensive code verification by solving a number of well-known test problems using RAPTOR and comparing its output to exact solutions. We also demonstrate convergence with existing polarized radiative-transfer codes in the context of complex astrophysical problems, where we found that the integrated flux densities for all Stokes parameters converged to excellent agreement. Conclusions. The RAPTOR code is capable of performing polarized radiative transfer in arbitrary, highly curved spacetimes. This capability is crucial for interpreting polarized observations of accreting black holes, which can yield information about the magnetic-field configuration in such accretion flows. The efficient formalism implemented in RAPTOR is computationally light and conceptually simple. The code is publicly available.

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