相关论文: Shadows of Lorentzian traversable wormholes

We study the influence of the plasma environment on the shadows of stationary axisymmetric wormholes. We consider a sample of several wormhole solutions and plasma distributions for which the Hamilton-Jacobi equation for the light rays is…

Black hole shadows and photon spheres offer valuable tools for investigating black hole properties. Recent observations by the Event Horizon Telescope Collaboration have confirmed the existence of rotating black holes. Black hole parameters…

We study slowly rotating traversable wormholes embedded in realistic galactic dark matter halos, including Navarro-Frenk-White (NFW), Bose-Einstein Condensate (Thomas-Fermi, TF), and pseudo-isothermal (PI) profiles. Using the Teo-type…

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…

Due to the gravitational lensing effect, a black hole casts a shadow larger than its horizon over a bright background, and the shape and size can be calculated. The Event Horizon Telescope collaboration has produced the first direct image…

The present paper is intended for studying the effect of strong gravitational lensing in the context of charged wormhole. To study this effect, the conditions determining the existence of photon spheres at and outside the throat are…

A brief illustrative discussion of the shadows of black holes at local and cosmological distances is presented. Starting from definition of the term and discussion of recent observations, we then investigate shadows at large, cosmological…

A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study the shadow cast by the five-dimensional Myers-Perry black hole with equal rotation parameters. We demonstrate that the null geodesic…

The study of shadow is quite prominent nowadays because of the ongoing Event Horizon Telescope\footnote{https://eventhorizontelescope.org/} observations. We construct the shadow images of charged wormholes in Einstein-Maxwell-dilaton (EMD)…

In this work, we present a theoretical analysis of null geodesics, critical photon orbits, and shadow formation associated with a wormhole generated by a geometric defect. The propagation of light in this spacetime is examined through the…

In this paper a class of expanding lorentzian traversable wormholes is discussed.

We describe the dynamical formation of the shadow of a collapsing star in a Hayward spacetime in terms of an observer far away from the center and a free falling observer. By solving the time-like and light-like radial geodesics we…

The first image of black hole in M87 galaxy taken by Event Horizon Telescope shows that directed observation of supermassive black holes would be a promising way to test general relativity in strong gravity field regime. In order to…

Higher dimensional theories admit astrophysical objects like supermassive black holes, which are rather different from standard ones, and their gravitational lensing features deviate from general relativity. It is well known that a black…

The shadows of black holes encode significant information about the properties of black holes and the spacetime surrounding them. So far, the effects of dispersive media, such as plasma, and relativistic aberration on the propagation 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 this work, we investigate the existence of wormholes within the framework of Loop Quantum Cosmology, using isotropic dark matter as the source. We analyze three distinct density profiles and solve the modified gravity field equations…

In this work, we explore for the first time slowly rotating traversable wormholes embedded in holographic dark energy. We focus on three representative holographic dark energy models -- R\'{e}nyi, mixed, and Moradpour -- and construct the…

The presence of a quintessence-like field can influence the black hole shadow through three primary mechanisms: the dynamics of accretion flows, the trajectories of photons, and the motion of observers. Unlike standard shadow analyses that…

The Lorentzian-Euclidean black hole has been recently introduced as a geodesically complete spacetime featuring a signature shift at the event horizon where causal geodesics are precluded from reaching the central $r=0$ singularity. In this…