相关论文: A new method for shadow calculations: application …

In this work, motivated by the fact that higher-dimensional theories predict the existence of black holes which differ from their four-dimensional counterpart, we analyse the geodesics and black hole shadow cast by a general non-extremal…

We propose a two-parameter, static and spherically symmetric regular geometry, which, for specific parameter values represents a regular black hole. The matter required to support such spacetimes within the framework of General Relativity…

The pursuit of a comprehensive theory of gravity has led to the exploration of various alternative models, necessitating a model-independent framework. The Konoplya-Rezzolla-Zhidenko (KRZ) parameterization offers a robust method for…

Einstein's theory of General Relativity predicts that the spacetime metric around astrophysical black holes is described by the Kerr solution. In this work, we employ state-of-the-art in relativistic reflection modeling to analyze a…

We establish a thermodynamic-optical duality that directly bridges the semiclassical quantum evaporation of black holes with their classical macroscopic geometry. By employing a diffeomorphic inversion, we re-parameterize the intrinsic…

The analysis of the properties of the X-ray radiation emitted from geometrically thin accretion disks around black holes can be a powerful tool to test General Relativity in the strong field regime. This chapter reviews the state-of-the-art…

In this paper, we employ a ray-tracing algorithm to simulate the shadows of three equal-mass black holes in static equilibrium across a wide parameter space. We find that the shadows consist of a larger primary shadow and several distorted,…

We discuss the optical appearance from thin accretion disks in parametrized black holes, namely, solutions characterized by an arbitrarily large number of parameters without any regards to the theory of the gravitational and matter fields…

Very Long Baseline Interferometry (VLBI) at sub-millimeter waves has the potential to image the shadow of the black hole in the Galactic Center, Sagittarius A* (Sgr A*), and thereby test basic predictions of the theory of general…

We discuss parameterizations of black-hole spacetimes in and beyond General Relativity in view of their symmetry constraints: within the class of axisymmetric, stationary spacetimes, we propose a parameterization that includes non-circular…

We study the black hole's shadow for Schwarzschild - de Sitter and Kerr - de Sitter metrics with the contribution of the cosmological constant \Lambda. Based on the reported parameters of the M87* black hole shadow we obtain constraints for…

Einstein's General Theory of Relativity (GR) successfully describes gravity. The most fundamental predictions of GR are black holes (BHs), but in spite of many convincing BH candidates in the Universe, there is no conclusive experimental…

Recently, Vagnozzi and Visinelli's work [Phys. Rev. D 100, 024020 (2020)] reveals that M87*'s shadow establishes an upper limit of $l \lesssim 170$ AU, where $l$ is the AdS$_5$ curvature radius and 1 AU is one astronomical unit. The Event…

We consider the black hole (BH) shadow images which can be restored by data processing and image recovery procedures in future space Very Large Baseline Interferometry (VLBI) missions. For Kerr BHs with masses and coordinates of SgrA*, M87*…

The Galactic Center black hole environment gives us new opportunity to test deviation from General Relativity and black hole physics. In this work we analytically generate the shape of the Galactic Center black hole by using a recently…

High-resolution, multi-wavelength, and time-domain observations of the Galactic centre black hole candidate, Sgr A*, allow for a direct test of contemporary accretion theory. To date, all models have assumed alignment between the accretion…

In this work, we investigate a spherically symmetric charged black hole in the presence of a Kalb--Ramond field background. We calculate the photon sphere and shadow radii and, corroborating our results, we constrain them from observational…

Artificial black holes (called also acoustic or optical black holes) are the black holes for the linear wave equation describing the wave propagation in a moving medium. They attracted a considerable interest of physicists who study them to…

Black hole accretion disks are a fascinating topic in astrophysics, as they play a crucial role in several high-energy situations. This paper investigates the optical appearance of scalar hairy black holes (SHBHs) with asymmetric potential,…

This work consists of two distinct parts. In the first part we present a new method for solving the initial value problem of general relativity. Given any spatial metric with a surface orthogonal Killing field and two freely specified…