Results 11 to 20 of about 55,471 (131)

Constraints on relic magnetic black holes

Journal of High Energy Physics, 2022
We present current direct and astrophysical limits on the cosmological abundance of black holes with extremal magnetic charge. Such black holes do not Hawking radiate, allowing those normally too light to survive to the present to do so.
Melissa D. Diamond, David E. Kaplan
doaj   +1 more source

Mergers of Supermassive Black Holes in Astrophysical Environments [PDF]

, 2011
Modeling the late inspiral and merger of supermassive black holes is central to understanding accretion processes and the conditions under which electromagnetic emission accompanies gravitational waves.
Armitage, Armitage, Artymowicz, Bode, Bogdanović, Cactus, Cao, Colpi, Deirdre Shoemaker, Einstein Toolkit, Gould, Hayasaki, James Healy, Kocsis, MacFadyen, Mahadevan, Milosavljević, Nemmen, O’Neill, Pablo Laguna, Roland Haas, Schnetter, Shakura, Sharma, Tamara Bogdanović, Tanja Bode, Thornburg, van Meter   +27 more
core   +3 more sources

Extremal bifurcations of rotating AdS4 black holes

Journal of High Energy Physics, 2021
The Weak Gravity Conjecture arises from the assertion that all extremal black holes, even those which are “classical” in the sense of being very massive, must decay by quantum-mechanical emission of particles or smaller black holes.
Brett McInnes
doaj   +1 more source

Physics of accretion flows around compact objects [PDF]

, 2006
Several physical and astrophysical problems related to accretion onto black holes and neutron stars are shortly reviewed. I discuss the observed differences between these two types of compact objects in quiescent Soft X-ray Transients.
Abramowicz, Abramowicz, Aharonian, Bahcall, Barceló, Bardeen, Bejger, Berti, Bildsten, Blandford, Blandford, Bondi, Buchdahl, Campana, Casares, Cattoen, Chapline, Chapline, Chapline, Chen, Chen, Davis, Deloye, Dubus, Dubus, Dyson, Fender, Fender, Gallo, Gammie, Goldston, Haensel, Haensel, Hartle, Hopkins, Hughes, Hughes, Ichimaru, Jean-Pierre Lasota, Jonker, Kesden, King, King, Krasnopolsky, Lasota, Lasota, Lasota, Lasota, Li, Mazur, Menou, Menou, Menou, Mirabel, Moderski, Moderski, Narayan, Narayan, Narayan, Narayan, Narayan, Narayan, Natarajan, Nelemans, Oppenheimer, Paczyński, Paczyński, Papaloizou, Rothman, Ruffini, Rutledge, Schunck, Schwarz, Schwarzschild, Schödel, Shafee, Sikora, Torres, Volonteri, Wilson, Yuan, Yungelson   +81 more
core   +3 more sources

Tidal forces in dirty black hole spacetimes

European Physical Journal C: Particles and Fields, 2022
Black holes can be inserted in very rich astrophysical environments, such as accretion disks. Although isolated black holes are simple objects in general relativity, their accretion disks may significantly enrich the field configurations of their ...
Haroldo C. D. Lima Junior, Mateus M. Corrêa, Caio F. B. Macedo, Luís C. B. Crispino   +3 more
doaj   +1 more source

Constraints on the Size of Extra Dimensions from the Orbital Evolution of the Black-Hole X-Ray Binary XTE J1118+480 [PDF]

, 2009
In a universe of the Randall-Sundrum type, black holes are unstable and emit gravitational modes in the extra dimension. This leads to dramatically shortened lifetimes of astrophysical black holes and to an observable change of the orbital period of ...
Johannsen, Tim
core   +2 more sources

Gravitational lensing by a Horndeski black hole

European Physical Journal C: Particles and Fields, 2017
In this article we study gravitational lensing by non-rotating and asymptotically flat black holes in Horndeski theory. By adopting the strong deflection limit, we calculate the deflection angle, from which we obtain the positions and the magnifications ...
Javier Badía, Ernesto F. Eiroa
doaj   +1 more source

Most Supermassive Black Holes must be Rapidly Rotating [PDF]

, 2001
We use the integrated spectrum of the X-ray background and quasars Spectral Energy Distribution to derive the contribution of quasars to the energy output of the Universe. We find a lower limit for the energy from accretion onto black holes of 6%, of the
Comastri A., G. Risaliti, G. Zamorani, Guainazzi M., M. Elvis, Mineo T., Miyaji T., Perola G. C., Perola G. C., Setti G., Yuan W.   +10 more
core   +2 more sources

Astrophysical evidence for the existence of black holes [PDF]

, 1999
Following a short account of the history of the idea of black holes, we present a review of the current status of the search for observational evidence of their existence aimed at an audience of relativists rather than astronomers or astrophysicists.
A Celotti, Abramowicz M A, Bahcall J N, Bergmann P G, Blandford R D, Blandford R D, Blandford R D, Blandford R D, Blandford R D, Bradt H V D, Carr B J, Carter B, Charles P A, D W Sciama, Eckart A, Eddington A S, Einstein A, Einstein A, Fabian A C, Fabian A C, Fabian A C, Haensel P, Harrison B K, Hawking S W, Hawking S W, Hawking S W, Israel W, J C Miller, Krolik J H, Laplace P S 1796, Lemaître G, Lodge O, Lynden-Bell D, Menou K, Michell J 1784, Miyoshi M, Prendergast K H, Rees M J, Rees M J, Richstone D O, Rothschild R E E, Schutz B F, Schwarzschild K, Shahbaz T, Shahbaz T, Shahbaz T, Shklovskii I S, Tanaka Y, van der Marel R   +48 more
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Rotating black holes in Horndeski gravity: thermodynamic and gravitational lensing

European Physical Journal C: Particles and Fields, 2022
The lack of rotating black holes, typically found in nature, hinders testing modified gravity from astrophysical observations. We present the axially symmetric counterpart of an existing spherical hairy black hole in Horndeski gravity having additional ...
Rahul Kumar Walia, Sunil D. Maharaj, Sushant G. Ghosh   +2 more
doaj   +1 more source