相关论文: Exotic compact objects and light bosonic fields

The images of supermassive black holes surrounded by optically-thin, radiatively-inefficient accretion flows, like those observed with the Event Horizon Telescope, are characterized by a bright ring of emission surrounding the black-hole…

Exotic objects such as the Ellis wormhole are expected to act as gravitational lenses. Much like their nonexotic counterparts, information about these lenses can be found by considering the strong and weak lensing fields they induce. In…

The distortion of the spacetime structure in the surroundings of black holes affects the trajectories of light rays. As a consequence, black holes can act as gravitational lenses. Observations of type Ia supernovas, show that our Universe…

Assuming that general relativity is the correct theory of gravity in the strong field limit, can gravitational wave observations distinguish between black hole and other compact object sources? Alternatively, can gravitational wave…

Geometrical inequalities show how certain parameters of a physical system set restrictions on other parameters. For instance, a black hole of given mass can not rotate too fast, or an ordinary object of given size can not have too much…

Astrophysical black holes are embedded in surrounding dark and baryonic matter that can measurably perturb the spacetime. We construct a self-consistent spacetime describing a slowly rotating black hole embedded in an external matter…

The search for solutions of Einstein's equations representing relativistic cosmological models with a discrete matter content has been remarkably fruitful in the last decade. In this review we discuss the progress made in the study of a…

Special and general relativistic effects on the X-ray emissions, especially the continuum spectra, from the accretion disks around black holes are investigated using the ray-tracing method. Because both the special and general relativistic…

For any multidimensional theory with compactified internal spaces, conformal excitations of the internal space metric result in gravitational excitons in the external spacetime. These excitations contribute either to dark matter or to cross…

Adopting the strong field limit approach, we investigated the strong gravitational lensing in a Brane-World black hole, which means that the strong field limit coefficients and the deflection angle in this gravitational field are obtained.…

It is now theoretically well established that not only a black hole can cast shadow, but other compact objects such as naked singularities, gravastar or boson stars can also cast shadows. An intriguing fact that has emerged is that the…

Using numerical methods we present the first full nonlinear study of phantom scalar field accreted into a black hole. We study different initial configurations and find that the accretion of the field into the black hole can reduce its area…

It is shown that space curvature can be disposed of by properly taking into account gravitational self energies. This leads to a parameter free modification of Newton's law, violating Gauss theorem, which accounts for the crucial tests of…

An Extended Uncertainty Principle inspired Schwarzschild metric that allows for large scale modifications to gravitation is presented. At a new fundamental length scale $\Ls$, the usual black hole characteristics (horizon radius, ISCO, and…

Using a noncommutative inspired Einstein-Euler-Heisenberg black hole, we analyse the associated graviton and light rings that together with the event horizon, provide the necessary components to build its shadow. An analysis of the angular…

Several dark matter models allow for the intriguing possibility of exotic compact object formation. These objects might have unique characteristics that set them apart from their baryonic counterparts. Furthermore, gravitational wave…

The astrophysical consequences of the presence of a quintessence scalar field on the evolution of the horizon and on the accretion disk surrounding a static black hole, in the Scalar-Vector-Tensor version of Modified Gravity (MOG), are…

The question of whether unobserved short-wavelength modes of the gravitational field can induce decoherence in the long-wavelength modes (``the decoherence of spacetime'') is addressed using a scalar field toy model with some features of…

Axion-like particles are hypothetical new light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the…

We provide an analytic method to discriminate among different types of black holes on the ground of their strong field gravitational lensing properties. We expand the deflection angle of the photon in the neighbourhood of complete capture,…