Related papers: Defect wormholes are defective
A radial deformation of the Kerr metric is studied which leads to the appearance of wormholes in certain cases. {\bf These wormholes can be thought of as being formed by two distinct but identical asymptotically non-flat spacetimes joined…
We study wormhole geometries embedded in an expanding universe within a four-scalar non-linear $\sigma$ model, where the target-space metric is identified with the spacetime Ricci tensor. In this framework, wormholes can remain stable even…
We present a discussion of the traversable wormholes in Einstein-Dirac-Maxwell theory recently reported in e-Print: 2010.07317. This includes a detailed description of the ansatz and junction condition, together with an investigation of the…
It is shown that the existence of static, cylindrically symmetric wormholes does not require violation of the weak or null energy conditions near the throat, and cylindrically symmetric wormhole geometries can appear with less exotic…
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…
We construct traversable thin-shell wormholes in the Dvali-Gabadadze-Porrati theory with cylindrical symmetry applying the cut and paste procedure to a flat black string solution of the five-dimensional vacuum Einstein field equations. In…
We study the stability of static, spherically symmetric, traversable wormholes with or without an electric charge, existing due to conformal continuations in a class of scalar-tensor theories with zero scalar field potential (so that…
In this paper we study traversable wormholes in the context of $f(R)$ gravity. Exact solutions of traversable wormholes are found by imposing the nonconstant Ricci scalar. These solutions asymptotically match spherical, flat and hyperbolic…
The C-metric in vacuum general relativity describes a pair of accelerated black holes supported by conical singularity. In this paper, we present a new family of exact solutions to the Einstein-phantom scalar system that describes…
We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported…
Exact solutions of traversable wormholes were recently found under the assumption of spherical symmetry and the existence of a non-static conformal symmetry. In this paper, we verify that in the case of the conformally symmetric spacetimes…
We study spherically symmetric, self-similar wormhole solutions supported by colliding streams of negative-energy null dust, and their dynamical formation. Under the assumption of self-similarity, the Einstein equations reduce to a system…
While wormholes are as good a prediction of Einstein's theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, holding a wormhole open requires a violation of the null energy condition,…
This thesis explores traversable wormhole (WH) solutions within symmetric teleparallel gravity and its extensions, including $f(Q)$ and $f(Q, T)$ gravity. Chapter I reviews WH geometry and properties, general relativity, and modified…
The aim of this paper is to report on the existence of a wide variety of exact solutions, ranging from black holes to wormholes, when a conformally coupled scalar field with a self interacting potential containing a linear, a cubic and a…
Although wormholes can be treated as topological objects in spacetime and from a global point-of-view, a precise definition of what a wormhole throat is and where it can be located can be developed and treated entirely in terms of local…
We examine the possibility of static wormhole solutions in the vacuum Brans-Dicke theory both in the original (Jordan) frame and in the conformally rescaled (Einstein) frame. It turns out that, in the former frame, wormholes exist only in a…
This paper investigates a particular type of wormhole. The wormhole solutions studied are obtained by sewing together two static, spherically symmetric, charged black-hole metrics at their horizons. The charged wormholes are in a background…
A multidimensional cosmological model with space-time consisting of $n (n \ge 2)$ Einstein spaces $M_{i}$ is investigated in the presence of a cosmological constant $\Lambda$ and a homogeneous minimally coupled scalar field $\varphi(t)$ as…
Einstein-Dirac-Maxwell wormholes are asymptotically flat static wormhole solutions in general relativity that do not make use of exotic matter. The asymmetric static solutions are smooth, are regular everywhere, and violate the null energy…