Related papers: Traversable ghost wormholes
In the standard approach to studying wormhole geometry, the presence of dark energy is unavoidable to ensure traversability. The dark energy provides the negative gravity effect to keep the throat open. The question we analyse is whether…
We present a systematic study of exact solutions for traversable wormhole geometries in a static and hyperbolic symmetric spacetime. In the conventional form of studying wormhole geometry, traversability requires the presence of exotic…
In this work, we present novel analytical solutions for static and spherically symmetric wormhole geometries threaded by an anisotropic distribution of matter conformally coupled to a scalar ghost field. We explore the main features of the…
Traversable wormholes have traditionally been viewed as intrinsically topological entities in some multiply connected spacetime. Here, we show that topology is too limited a tool to accurately characterize a generic traversable wormhole: in…
We construct explicit examples of globally regular static, spherically symmetric solutions in general relativity with scalar and electromagnetic fields describing traversable wormholes with flat and AdS asymptotics and regular black holes,…
We construct models of two exotic objects: (i) a wormhole whose throat is hidden by a stellar object like a neutron star; and (ii) a wormhole inside a black hole. We work within Einstein's gravity coupled to two scalar fields with a…
Wormholes and black holes have traditionally been treated a quite separate objects with relatively little overlap. The possibility of a connection arises in that wormholes, if they exist, might have profound influence on black holes, their…
We construct examples of static, spherically symmetric wormhole solutions in general relativity with a minimally coupled scalar field $\phi$ whose kinetic energy is negative in a restricted region of space near the throat (of arbitrary…
A possible candidate for the present accelerated expansion of the Universe is ''phantom energy'', which possesses an equation of state of the form $\omega\equiv p/\rho<-1$, consequently violating the null energy condition. As this is the…
We construct explicit examples of globally regular static, spherically symmetric solutions in general relativity with scalar and electromagnetic fields, describing traversable wormholes with flat and AdS asymptotics and regular black holes,…
We investigate possible manifolds characterizing traversable wormholes in the presence of a scalar field minimally coupled to gravity, which has both kinetic and potential energy. The feature of traversability requires the violation of the…
In this paper, we construct models that admit the traversable wormhole geometries in the framework of Einstein's gravity with two scalar fields. As well known, the energy conditions are broken and we show that there appears a ghost. The…
In the context of General Relativity (GR), violation of the null energy condition (NEC) is necessary for existence of static spherically symmetric wormhole solutions. Also, it is a well-known fact that the energy conditions are violated by…
We consider static spherically symmetric wormhole configurations in a gravitational theory of a scalar field with a potential $V(\phi)$ and nonminimal derivative coupling to the curvature describing by the term $(\epsilon g_{\mu\nu} +…
In this paper, we formulate wormhole-plus-neutron-star (WH+NS) systems supported by two scalar fields, allowing for both pressure anisotropy of the neutron fluid and magnetic field. In general, such WH+NS systems contain ghosts; however,…
It has been suggested that a possible candidate for the present accelerated expansion of the Universe is ''phantom energy''. The latter possesses an equation of state of the form $\omega\equiv p/\rho<-1$, consequently violating the null…
We construct exact nonstatic nonhomogeneous spherically symmetric solutions in the theory of gravity with a scalar field possessing the exponential potential. The solution of particular interest corresponds to the scalar field with negative…
Exact solutions of traversable wormholes are found under the assumption of spherical symmetry and the existence of a {\it non-static} conformal symmetry, which presents a more systematic approach in searching for exact wormhole solutions.…
It was argued in literature that traversable wormholes can exist with arbitrarily small violation of null energy conditions. We show that if the amount of exotic material near the wormhole throat tends to zero, either this leads to a horn…
This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density $\sigma$ is positive, while the surface…