Absorption and scattering of a black hole with a global monopole in f(R) gravity

We consider the absorption problem for a massless scalar field propagating in static and spherically symmetric black holes of arbitrary dimension endowed with a photon sphere. For this wide class of black holes, we show that the fluctuations of the high-energy absorption cross section are totally and very simply described from the properties (dispersion relation and damping) of the waves trapped near the photon sphere and therefore, in the eikonal regime, from the characteris...

We investigate the problem of scattering and conversion of monochromatic planar gravitational and electromagnetic waves impinging upon a Reissner-Nordstr\"om black hole using a Regge pole description, i.e., a complex angular momentum approach. For this purpose, we first compute numerically the Regge pole spectrum for various charge-to-mass ratio configurations. We then derive an asymptotic expressions for the lowest Regge poles, and by considering Bohr-Sommerfeld-type quantiz...

We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all ma...

We study the scattering of monochromatic planar scalar waves in a geometry that interpolates between the Schwarzschild solution, regular black holes and traversable wormhole spacetimes. We employ the partial waves approach to compute the differential scattering cross section of the regular black hole, as well as of the wormhole solutions. We compare our full numerical results with the classical geodesic scattering and the glory approximation, obtaining excellent agreement in ...

We consider effects of non-uniformity of quasi-spherical small black hole horizons on scattering massless spineless particles in the long-wave approximation. Focusing on 4D flat and AdS neutral black hole backgrounds with conformally spherical geometry of the horizon, we observe the notable differences in compare to the scattering process on the spherically-symmetric black holes. In particular, the absorption cross-section becomes dependent on both, polar and azimuthal, spher...

We study the absorption of massless scalar field by two types furry charged black holes in de Rham-Gabadadze-Tolley (dRGT) theory. The absorption cross section is calculated in high frequency limit $\sigma_{hf}$ and low frequency limit $\sigma_{lf}$. We show that the high frequency limit $\sigma_{hf}$ is the area of shadow and the low frequency limit $\sigma_{lf}$ is the area of horizon. The ratio $R_{f}=\frac{\sigma_{hf}}{\sigma_{lf}}$ is used to measure the impact of char...

This is a study of the scattering and absorption of planar gravitational waves by a Kerr black hole in vacuum. We apply the partial wave method to compute cross sections for the special case of radiation incident along the rotation axis. A catalogue of numerically-accurate cross sections is presented, for a range of incident wavelengths $M\omega \le 4$ and rotation rates $a \le 0.999M$. Three effects are studied in detail: polarization, helicity-reversal and glory scattering....

We discuss the phenomenology of massless scalar fields around a regular Bardeen black hole, namely absorption cross section, scattering cross section and quasinormal modes. We compare the Bardeen and Reissner-Nordstr\"om black holes, showing limiting cases for which their properties are similar.

This paper aims to investigate the scattering of fermions by spherically symmetric MOG black holes, which are a type of black holes encountered in scalar-tensor-vector modified gravitational theories. After determining the scattering modes in this black hole geometry, we apply the partial wave method to compute analytical expressions for the phase shifts that enter into the definition of scattering amplitudes. An analysis of the influence of the MOG parameter $\alpha$ on the ...

In this work, we re-assess a class of black hole solutions in a global monopole spacetime in the framework of an $f(R)$-gravity model. Our main line of investigation consists in considering a region close enough to the black hole, but such that the weak field approximation is still valid. The stability of the black hole is studied in terms of its thermodynamical properties, with the radial coordinate written as a power law function with the status of the main factor underneat...