We construct evolutionary models of the populations of active galactic nuclei (AGN) and supermassive black holes, in which the black hole mass function grows at the rate implied by the observed luminosity function, given assumptions about the radiative efficiency and the luminosity in Eddington units. We draw on a variety of recent X-ray and optical measurements to estimate the bolometric AGN l...

It has recently been shown that the uniqueness theorem for stationary black holes cannot be extended to five dimensions. However, uniqueness is an important assumption of the string theory black hole entropy calculations. This paper justifies this assumption by proving a uniqueness theorem for supersymmetric black holes in five dimensions. Some remarks concerning general properties of non-super...

Recently there has been a considerable resurgence in the no scalar hair theorem for black holes. Investigations regarding no hair theorem, however, had started about thirty years ago [1]. Inspired by Israel’s uniqueness theorem for Schwarzschild and Reissner–Nordstrom black holes [2] and Carter [3] and Wald’s [4] uniqueness theorem for Kerr black holes, Wheeler anticipated that gravitational co...

We have developed a numerical code to study the evolution of distorted, rotating black holes. This code is used to evolve a new family of black hole initial data sets corresponding to distorted “Kerr” holes with a wide range of rotation parameters, and distorted Schwarzschild black holes with oddparity radiation. Rotating black holes with rotation parameters as high as a/m = 0.87 are evolved an...

1 OF ALL the legacies of Einstein’s general theory of relativity, none is more fascinating than black holes. While we now almost take their existence for granted, for much of the 20th century black holes were viewed as mathematical curiosities with no counterparts in nature. Einstein himself never believed in black holes and wrote two papers in which he argued against their existence. Einstein’...

We apply Brown-Henneaux’s method to the 5D extremal rotating Kaluza-Klein black holes essentially following the calculation of the Kerr/CFT correspondence, which is not based on supersymmetry nor string theory. We find that there are two completely different Virasoro algebras that can be obtained as the asymptotic symmetry algebras according to appropriate boundary conditions. The microscopic e...

We consider the evolution of primordial black holes in a generalized Jordan-BransDicke cosmological model where both the Brans-Dicke scalar field and its coupling to gravity are dynamical functions determined from the evolution equations. The evaporation rate for the black holes is different from the case in standard cosmology. We show that the accretion of radiation can proceed effectively in ...

Anisotropic emission of gravitational waves during the merger or formation of black holes can lead to the ejection of these black holes from their host galaxies. A recoiled black hole which moves on an almost radial bound orbit outside the virial radius of its central galaxy, in the cold dark matter background, reaches its apapsis in a finite time. The low value of dark matter velocity dispersi...

We present a new model for the formation of black holes in cosmological simulations, motivated by the first star formation. Black holes form from high density peaks of primordial gas, and grow via both gas accretion and mergers. Massive black holes heat the surrounding material, suppressing star formation at the centres of galaxies, and driving galactic winds. We perform an investigation into t...

Gravitational waves can be used as a way to investigate the structure of spacetime. Loop Quantum Gravity is a theory that propose a way to model the behavior of spacetime in situations where its atomic characteristic arises. Among these situations, the spacetime behavior near the Big Bang or black hole’s singularity. A recent prediction of loop quantum gravity is the existence of sub-Planckian ...