相关论文: Evolution of black hole shadows from superradiance

We have studied the shadow of a disformal Kerr black hole with an extra deformation parameter, which belongs to non-stealth rotating solutions in quadratic Degenerate Higher Order Scalar Tensor (DHOST) theory. Our result show that the size…

The study of astrophysical phenomena like black hole shadows is an effective approach to properly understand the modified gravity and explore its validity. Motivated by recent astrophysical observations, we consider a black hole (BH) in…

Light bosonic degrees of freedom have become a serious candidate for dark matter. The evolution of these fields around curved spacetimes is poorly understood but is expected to display interesting effects. In particular, the interaction of…

A detailed analysis is presented of gravitational microlensing by intervening compact objects of the black hole shadows imaged by the Event Horizon Telescope (EHT). We show how the center, size, and shape of the shadow depend on the…

In rotating black hole background surrounded by dark matter, we investigated the super-radiant phenomenon of massive scalar field and its associated instability.Using the method of asymptotic matching, we computed the amplification factor…

We study the influence of the cosmic expansion on the size of the shadow of a spinning black hole observed by a comoving observer. We first consider that the expansion is driven by a cosmological constant only and build the connection…

Ultralight bosonic fields in the mass range $\sim (10^{-20}-10^{-11})\,{\rm eV}$ can trigger a superradiant instability that extracts energy and angular momentum from an astrophysical black hole with mass $M\sim(5,10^{10})M_\odot$, forming…

Accreting black holes tend to display a characteristic dark central region called the black-hole shadow, which depends only on spacetime/observer geometry and which conveys information about the black hole's mass and spin. Conversely, the…

In a recent work on rotating black hole shadows [Phys. Rev. D{\bf 101}, 084029 (2020)], we proposed a new approach for calculating size and shape of the shadows in terms of astrometrical observables with respect to finite-distance…

Black hole superradiance provides a window into the dynamics of light scalar fields and their interactions close to a rotating black hole. Due to the rotation of the black hole, the amplitude of the scalar field becomes magnified, leading…

In this article we consider the formation and evolution of black holes, especially those in binary stars where radiation from the matter falling on them can be seen. We consider a number of effects introduced by some of us, which are not…

We have studied the shadows of a Schwarzschild black hole surrounded by a Bach-Weyl ring through the backward ray-tracing method. The presence of Bach-Weyl ring leads to that the photon dynamical system is non-integrable and then chaos…

By considering the celestial light source and the thin disk source, we employ the backward ray-tracing method to carefully study the shadow, inner shadow and observational images of the non-singular rotating black holes in loop quantum…

The existence of black hole shadows is one of the most interesting effects of the strong field regime of general relativity (GR). Recent observations by the Event Horizon Telescope (EHT) have provided high-resolution images of the vicinity…

The shadow of a black hole is usually calculated, either analytically or numerically, on the assumption that the black hole is eternal, i.e., that it existed for all time. Here we ask the question of how this shadow comes about in the…

We investigate the shadow behaviors of the superentropic black holes in arbitrary dimensions. Using the Hamilton-Jacobi mechanism, we first obtain the associated null geodesic equations of motion. By help of a spheric stereographic…

In this work, we investigate the shadow properties of the Kerr-Newman-Anti-de Sitter black hole coupled to a nonlinear electrodynamics. We construct the shadow by employing the celestial coordinate approach for observers located at finite…

A distinct visual signature occurs in black holes that are surrounded by optically thin and geometrically thick emission regions. This signature is a sharp-edged dip in brightness that is coincident with the black-hole shadow, which is the…

Ultralight bosons, as important candidates of dark matter, can condense around spinning black holes (BHs) to form long-lived ``boson clouds'' due to superradiance instability. The boson-BH system can be observed through gravitational wave…

This work devotes to investigate the dynamical emergence of black hole shadow from gravitational lensing in dynamical spacetime by using the collapsing boson star. Two characterized scenarios are adopted with or without considering the time…