Related papers: Absorption section for black holes surrounded by s…
Obtaining black hole solutions in alternative theories of gravity can be a difficult task due to cumbersome field equations that arise in many of such theories. In order to study the strong field regime in a model-free approach, one can…
We examine the motion of the massless scalar field and nearly bound null geodesics in the near-ring region of a black hole, which may possess either acceleration or a gravitomagnetic mass. Around such black holes, the photon ring deviates…
We analyze the low frequency absorption cross section of minimally coupled massless scalar fields by different kinds of charged static black holes in string theory, namely the D1-D5 system in d=5 and a four dimensional dyonic four-charged…
In this work we have studied the scattering of scalar field around an extended black hole in F(R) gravity using WKB method. We have obtained the wave function in different regions such as near the horizon region, away from horizon and far…
In this short talk we review our results from the paper hep-th/0604075 with the main stress on the issues of causality and acoustic metric in eikonal approximation. In addition we correct the formula for the redshift of sound signals from…
We analyze the scalar radiation emitted by a source in a circular geodesic orbit around a spherically symmetric black hole. The black hole spacetime considered is quite general, in the sense that it encompasses the solutions of…
We calculate the absorption rates of fixed scalars by near extremal five dimensional black holes carrying general one-brane and five-brane charges by semi-classical and D-brane methods. We find that the absorption cross-sections do not in…
We study the scattering of charged massive particles impinging on a Reissner-Nordstr\"{o}m (RN) black hole immersed in perfect fluid dark matter (PFDM). We obtain an approximation of absorption cross section in the low-frequency regime via…
In this article, we report our study on the absorption cross section for the electromagnetic field due to static spherically symmetric regular black holes of two distinct categories: the Fan-Wang generic class and the Simpson-Visser class.…
Superradiance has been studied quite extensively in the context of static (charged) and rotating black hole spacetime. In this paper, we report for the first time that for a minimally coupled scalar field, the absorption cross-section of a…
We derive the absorption cross section of a minimally coupled scalar in the Lifshitz black hole obtained from the new massive gravity. The absorption cross section reduces to the horizon area in the low energy and massless limit of s-wave…
In this paper we compute the low energy absorption cross-section for minimally coupled massles scalars and spin-$1/2$ particles, into a general spherically symmetric black hole in arbitrary dimensions. The scalars have a cross section equal…
In the present work, we study the scattering for a black hole described by the canonical acoustic metric with Lorentz violation using asymptotic and numerical methods. In this scenario, we also check the effects of quasinormal modes and the…
The absorption and emission spectra for the minimally-coupled brane and bulk scalar fields are numerically computed when the spacetime is a $5d$ rotating black hole carrying the two different angular momentum parameters $a$ and $b$. The…
In this paper, we study the scattering and absorption sections of the Schwarzschild--anti de Sitter black hole surrounded by quintessence. The critical values of the cosmological constant and the normalization factor are obtained. We…
I describe some examples in support of the conjecture that the horizon area of a near equilibrium black hole is an adiabatic invariant. These include a Schwarzschild black hole perturbed by quasistatic scalar fields (which may be minimally…
Using numerical simulations we study the accretion of a phantom scalar field into a black hole and track the black hole horizon shrinking process. We integrate the amount of field left outside the black hole during the process in terms of…
The hypothesis that classical scalar fields could constitute dark matter on galactic and cosmic scales has garnered significant interest. In scenarios where supermassive black holes (SMBHs) form through the accretion of matter onto black…
We study about an approximation method of the Hawking radiation. We analyze an massless scalar field in exotic black hole backgrounds models which have peculiar properties in black hole thermodynamics (monopole black hole in SO(3)…
The absorption of photons and fermions into four-dimensional black holes is described by equations which in certain cases can be analyzed using dyadic index techniques. The resulting absorption cross-sections for near-extremal black holes…