Related papers: The wormhole hazard
One way to explain the present acceleration of the Universe is Einstein's cosmological constant. It is quite likely, in view of some recent studies, that a time-dependent equation of state had caused the Universe to evolve from an earlier…
We investigate whether a dynamical wormhole could survive in a universe that undergoes a cosmological bounce. First, the conditions under which a wormhole could persist from a contracting to an expanding phase of the cosmos are presented.…
Traversable wormholes necessarily require violations of the averaged null energy condition; this being the definition of ``exotic matter''. However, the theorems which guarantee the energy condition violation are remarkably silent when it…
We propose wormholes solutions by assuming space dependent equation of state parameter. Our models show that the existence of wormholes is supported by arbitrary small quantities of averaged null energy condition (ANEC) violating phantom…
Wormholes are extremely attractive objects for research, and although many mathematical and physical properties of these objects have been discovered and studied in the recent decades, there remain many unsolved problems and opportunities…
Experiments over three decades have been unable to demonstrate weak nonlocality in the sense of Bell unambiguously, without loopholes. The last important loophole remaining is the detection loophole, which is being tackled by at least three…
We discuss different arguments that have been raised against the viability of the big trip process, reaching the conclusions that this process can actually occur by accretion of phantom energy onto the wormholes and that it is stable and…
Static, spherically symmetric, traversable wormholes, induced by massless, nonminimally coupled scalar fields in general relativity, are shown to be unstable under spherically symmetric perturbations. The instability is related to…
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 causality properties of space-time models with traversable wormholes are considered. It is shown that relativity principle cannot be applied to the motion of the wormhole's mouths in the outer space and the dynamical wormhole…
A very simple wormhole geometry is considered as a model of a mode of topological fluctutation in Planck-scale spacetime foam. Quantum dynamics of the hole reduces to quantum mechanics of one variable, throat radius, and admits a WKB…
It has been suggested that the cosmological constant is a variable dynamical quantity. A class of solution has been presented for the spherically symmetric space time describing wormholes by assuming the erstwhile cosmological constant…
We study radial perturbations of a wormhole in $R^2$ gravity to determine regions of stability. We also investigate massive and massless particle orbits and tidal forces in this space-time for a radially infalling observer.
Static, spherically symmetric, traversable wormhole solutions with electric or magnetic charges are shown to exist in general relativity in the presence of scalar fields nonminimally coupled to gravity. These wormholes, however, turn out to…
This paper reexamines a special class of thin-shell wormholes that are unstable in general relativity in the framework of noncommutative geometry. It is shown that as a consequence of the intrinsic uncertainty these wormholes are stable to…
Exact wormhole solutions, while eagerly sought after, often have the appearance of being overly specialized or highly artificial. A case for the possible existence of traversable wormholes would be more compelling if an abundance of…
The energy conditions of general relativity permit one to deduce very powerful and general theorems about the behaviour of strong gravitational fields and cosmological geometries. However, the energy conditions these theorems are based on…
We have studied the stability of wormhole geometries, under massless scalar, electromagnetic and axial gravitational perturbations, in the context of higher dimensional spacetimes. Intriguingly, the construction of a wormhole spacetime in…
Wormholes are hypothetical shortcuts in spacetime that in General Relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard \emph{designer}…
Spacetime wormholes are evidently an essential component of the construction of a time machine. Within the context of general relativity, such objects require, for their formation, exotic matter -- matter that violates at least one of the…