Related papers: Comment on "Observing a wormhole"
Black holes in general relativity are characterized by their trapping horizon, a one-way membrane that can be crossed only inwards. The existence of trapping horizons in astrophysical black holes can be tested observationally using a…
Black hole complementarity is incompatible with the existence of traversable wormholes. In fact, traversable wormholes cause problems for any theory where information comes out in the Hawking radiation.
The second-generation beam combiner at the Very Large Telescope (VLT), GRAVITY, observes the stars orbiting the compact object located at the center of our galaxy, with an unprecedented astrometric accuracy of 10 $\mu$as. The nature of this…
In the present article, models of traversable wormholes within the $f(R, T)$ modified gravity theory are investigated. We have presented some wormhole models, developed from various hypothesis for the substance of their matter, i.e. various…
For various reasons a number of authors have mooted an "exponential form" for the spacetime metric: \[ ds^2 = - e^{-2m/r} dt^2 + e^{+2m/r}\{dr^2 + r^2(d\theta^2+\sin^2\theta \, d\phi^2)\}. \] While the weak-field behaviour matches nicely…
Unique features of particle orbits produce novel signatures of gravitational observable phenomena, and are quite useful in testing compact astrophysical objects in general relativity or modified theories of gravity. Here we observe a…
One of the most interesting astronomical objects is the Galactic Center. We concentrate our discussion on a theoretical analysis of observational data of bright stars in the IR-band obtained with large telescopes. We also discuss the…
We study shadows cast by a certain class of rotating wormholes and point out the crucial role of a rotating wormhole throat in the formation of a shadow. Overlooking this crucial role of a wormhole throat has resulted incomplete results in…
Acoustic oscillations in stars can be driven by gravitational waves. However, at present it is not feasible to use the helioseismology data for their detection, since it is impossible to disentangle the uncertain driving contributions…
Higher-dimensional black holes have long been considered within the context of brane worlds. Recently, it was shown that the brane-world ethos also permits the consideration of higher-dimensional wormholes. When such a wormhole, preexisting…
We study the stability and the scattering properties of a spacetime with a topological defect along a spherical bubble. This bubble connects two flat spacetimes which are asymptotically Minkowski, so that the resulting universe may be…
We construct boson star solutions in the presence of a phantom field, allowing for a nontrivial topology of the solutions. The wormholes residing at the core of the configurations lead to a number of qualitative changes of the boson star…
The work is devoted to the study of the possibilities of observational manifestations of traversable wormholes (WHs). The simplest binary system model consisting of a traversable WH candidate (black hole (BH), supermassive BH) and a…
In the presence of a Weyl scaling invariant cosmological action, black holes no longer have an event horizon and an apparent horizon. So they have no trapped surfaces, and may be "leaky", emitting a "black hole wind" which could lead to…
When a planet passes in front of a starspot during a transit of its host star, it causes a small upward blip in the light curve. Modelling the transit with the starspot allows the size, brightness and position of the spot to be measured. If…
We explore the shadow of certain class of rotating traversable wormholes within classical general relativity. The images depend on the angular momentum of the wormhole, and the inclination angle of the observer. We compare the results with…
Recent implications of results from quantum information theory applied to black holes has led to the confusing conclusions that requires either abandoning the equivalence principle (e.g. the firewall picture), or the no-hair theorem (e.g.…
{\it Hunting} compact astrophysical objects such as black holes and wormholes, as well as testing gravity theories, are important issues in relativistic astrophysics. In this sense, theoretical and observational studies of quasiperiodic…
In general relativity, traversable wormholes are possible provided they do not represent shortcuts in the spacetime. Einstein equations, together with the achronal averaged null energy condition, demand to take longer for an observer to go…
Black holes play a pivotal role in the foundations of physics, but there is an alarming discrepancy between what is considered to be a black hole in observational astronomy and theoretical studies. Despite claims to the contrary, we argue…