88 citations · 112 across the 16 of their papers we have counts for
16 papers
Absorption and scattering spectra of massive scalar waves in charged regular black hole spacetimes
Marco A. A. Paula, Carolina L. Benone, Luís C. B. Crispino
Regular black holes (RBHs) can be seen as possible alternatives to standard black holes (BHs), since these geometries do not have a curvature singularity. As a way of improving our…
Interaction of the gravitational Hawking radiation and a static point mass
João P. B. Brito, Atsushi Higuchi, Luís C. B. Crispino
We study the interaction of a stress-energy tensor describing a static point mass supported by a string outside a Schwarzschild black hole with the gravitons of the Hawking radiati…
Two shadows of a single black hole: Vacuum birefringence phenomena within Einstein-nonlinear-electrodynamics
Marco A. A. de Paula, Haroldo C. D. Lima, Pedro V. P. Cunha +2
One of the main features of nonlinear electrodynamics is the existence of an effective geometry that describes the geodesic motion of photons. A detailed analysis of the properties…
Multipole decomposition of the gravitational field of a point mass at the black hole horizon
João P. B. Brito, Atsushi Higuchi, Luís C. B. Crispino
The portion of the gravitational energy absorbed by the black hole due to the radial infall of a point mass is known to diverge at leading order in perturbation theory. This diverg…
Hairy black holes via gravitational decoupling: light rings, absorption and spectral lines
Gabriel P. Ribeiro, Renan B. Magalhães, Luís C. B. Crispino
We investigate the absorption of massless scalar waves by three distinct hairy black hole solutions obtained through the gravitational decoupling method, considering the weak, the…
Spectral lines of dirty wormholes
Leonardo K. S. Furuta, Renan B. Magalhães, Haroldo C. D. Lima Junior +1
Astrophysical objects like black holes are usually surrounded by matter in the form of accretion disks or jets of matter. These astrophysical scenarios are expected to introduce no…
Electromagnetic radiation from circular orbits in Schwarzschild--de Sitter spacetime
João P. B. Brito, Rafael P. Bernar, Luís C. B. Crispino
We investigate the electromagnetic radiation emitted by a charged particle orbiting a four-dimensional Schwarzschild--de Sitter black hole using a semiclassical approach. We calcul…
Spherical Einstein-Friedberg-Lee-Sirlin boson stars: Self-interacting solutions and their astrophysical appearance
Pedro L. Brito de Sá, Haroldo C. D. Lima, Carlos A. R. Herdeiro +1
We investigate boson stars within the framework of the self-interacting Einstein-Friedberg-Lee-Sirlin (E-FLS) model, constituted by a complex scalar field with a quartic self-inter…
Spinning generalizations of Majumdar-Papapetrou multi-black hole spacetimes: light rings, lensing and shadows
Zeus S. Moreira, Carlos A. R. Herdeiro, Luís C. B. Crispino
A generalization of the Majumdar-Papapetrou multi-black hole spacetime was recently constructed by Teo and Wan [1], describing charged and spinning (extremal) balanced black holes…
Larmor radiation as a witness to the Unruh effect
Atsushi Higuchi, George E. A. Matsas, Daniel A. T. Vanzella +5
We discuss the emission of radiation from general sources in quantum scalar, electromagnetic and gravitational fields using the Rindler coordinate frame, which is suitable for a un…
Sufficient conditions for unbounded superradiance in black hole spacetimes sourced by nonlinear electrodynamics
Marco A. A. de Paula, Luiz C. S. Leite, Luís C. B. Crispino
Recently, it has been reported that black holes (BHs) sourced by nonlinear electrodynamics (NED) can trigger unbounded superradiance, i. e., the total absorption cross section -- t…
Good tachyons, bad bradyons: role reversal in Einstein-nonlinear-electrodynamics models
Marco A. A. de Paula, Haroldo C. D. Lima Junior, Pedro V. P. Cunha +2
In relativistic mechanics, the 4-velocity and the 4-momentum need not be parallel. This allows their norm to have a different sign. This possibility occurs in nonlinear electrodyna…
Nonminimally coupled scalar field in Schwarzschild--de Sitter spacetime: Geodesic synchrotron radiation
João P. B. Brito, Rafael P. Bernar, Luís C. B. Crispino
We analyze the scalar radiation emitted by a source interacting with a nonminimally coupled scalar field in four-dimensional Schwarzschild--de Sitter spacetime. We obtain the emiss…
Semiclassical bremsstrahlung from a charge radially falling into a Schwarzschild black hole
João P. B. Brito, Rafael P. Bernar, Atsushi Higuchi +1
A semiclassical investigation of the electromagnetic radiation emitted by a charged particle in a radially freely falling motion in Schwarzschild spacetime is carried out. We use q…
Traversable wormholes and light rings
Sérgio V. M. C. B. Xavier, Carlos A. R. Herdeiro, Luís C. B. Crispino
Ultracompact objects (UCOs) are horizonless compact objects that present light rings (LRs) - circular photon orbits. As a result, they could be black hole mimickers. Some years ago…
Quantization of the electromagnetic field outside static black holes and its application to low-energy phenomena
L. C. B. Crispino, A. Higuchi, G. E. A. Matsas
We discuss the Gupta-Bleuler quantization of the free electromagnetic field outside static black holes in the Boulware vacuum. We use a gauge which reduces to the Feynman gauge in…