Results 41 to 50 of about 2,057,503 (206)

Gravitational lensing by a Horndeski black hole

open access: yesEuropean 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

Supermassive black holes in the early universe [PDF]

open access: yesContemporary Physics, 2019
22 pages, 9 figures, Invited Review, Contemporary Physics, in ...
Aaron Smith, Volker Bromm
openaire   +2 more sources

Classical and thermodynamic stability of black holes [PDF]

open access: yes, 2010
We consider the stability of black holes within both classical general relativity and the semiclassical thermodynamic description. In particular, we study linearised perturbations and their contributions to the gravitational partition function. Exploring

core   +2 more sources

Supermassive Black Holes [PDF]

open access: yesJournal of High Energy Physics, Gravitation and Cosmology, 2019
In the following black hole model, electrons and positrons form a neutral gas which is confined by gravitation. The smaller masses are supported against gravity by electron degeneracy pressure. Larger masses are supported by ideal gas and radiation pressure. In each case, the gas is a polytrope which satisfies the Lane-Emden equation.
openaire   +2 more sources

Formation of Supermassive Black Hole Seeds [PDF]

open access: yesPublications of the Astronomical Society of Australia, 2016
AbstractThe detection of quasars at z > 6 unveils the presence of supermassive black holes of a few billion solar masses. The rapid formation process of these extreme objects remains a fascinating and open issue. Such discovery implies that seed black holes must have formed early on, and grown via either rapid accretion or BH/galaxy mergers. In this
Latif, M., FERRARA, ANDREA
openaire   +2 more sources

Eötvös experiments with supermassive black holes [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2016
By examining the locations of central black holes in two elliptical galaxies, M\,32 and M\,87, we derive constraints on the violation of the strong equivalence principle for purely gravitational objects, i.e. black holes, of less than about two-thirds, $η_N<0.68$ from the gravitational interaction of M\,87 with its neighbours in the Virgo cluster ...
Asvathaman, Asha   +2 more
openaire   +1 more source

Aharonov–Bohm Effect for Cooper Pairs in Kerr Spacetime: Gravitomagnetic Phase Shifts From Frame Dragging

open access: yesAnnalen der Physik, Volume 538, Issue 8, August 2026.
ABSTRACT The unification of quantum mechanics and general relativity remains a central problem in fundamental physics. Here, we study the gravitomagnetic Aharonov–Bohm (AB) effect for Cooper pairs in Kerr spacetime. Frame‐dragging by a rotating black hole (BH) generates an effective vector potential through the off‐diagonal metric term gtϕ$g_{t\phi }$,
Erdem Sucu, İzzet Sakallı
wiley   +1 more source

Supermassive Black Hole Growth in Hierarchically Merging Nuclear Star Clusters

open access: yesThe Astrophysical Journal
Supermassive black holes are prevalent at the centers of massive galaxies, and their masses scale with galaxy properties, increasing evidence suggesting that these trends continue to low stellar masses.
Konstantinos Kritos   +7 more
doaj   +1 more source

First Detection of an Overmassive Black Hole Galaxy UHZ1: Evidence for Heavy Black Hole Seed Formation from Direct Collapse

open access: yesThe Astrophysical Journal Letters, 2023
The recent Chandra-JWST discovery of a quasar in the z ≈ 10.1 galaxy UHZ1 reveals that accreting supermassive black holes were already in place 470 million years after the Big Bang. The Chandra X-ray source detected in UHZ1 is a Compton-thick quasar with
Priyamvada Natarajan   +5 more
doaj   +1 more source

Primordial black holes as dark matter candidates

open access: yesSciPost Physics Lecture Notes, 2022
We review the formation and evaporation of primordial black holes (PBHs) and their possible contribution to dark matter. Various constraints suggest they could only provide most of it in the mass windows $10^{17}$ - $10^{23}\,$g or $10$ - $10^{2}\,M_ ...
Bernard Carr, Florian Kuhnel
doaj   +1 more source

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