Related papers: Thin-shell wormholes in 2+1-dimensional Einstein-S…
A detailed study of quantum and semiclassical Euclidean wormholes for Einstein's theory with a minimally coupled scalar field has been performed for a class of potentials. Massless, constant, massive (quadratic in the scalar field) and…
In this article, we study thin shells of matter connecting charged black string geometries with different values of the corresponding parameters. We analyze the matter content and the mechanical stability of the shells undergoing…
The vacuum polarization of the quantized scalar field with non-conformal coupling $\xi$ on the long throat of a wormhole background is calculated. It is shown that the stress-energy tensor of vacuum fluctuations in considered spacetime is…
We reconsider the issue of whether scalar-tensor theories can admit stable wormhole configurations supported by a non-trivial radial profile for the scalar field. Using a recently proposed effective theory for perturbations around static,…
Spherically symmetric thin-shell wormholes are constructed within the framework of Brans-Dicke gravity. It is shown that, for appropriate values of the Brans-Dicke constant, these wormholes can be supported by matter satisfying the energy…
We study charged black hole and wormhole solutions of Type 0A/IIA string theory in two dimensions. There is a competition between Euclidean wormholes and near extremal black holes in the thermodynamic ensemble. In a certain regime of phase…
In this paper, we construct an intra-galactic thin shell wormhole joining two copies of identical galactic space times described by the Mannheim-Kazanas de Sitter solution in conformal gravity and study its stability under spherical…
We employ an old field theory model, formulated and discussed by Born, Infeld, Hoffman and Rosen during 1930s. Our method of cutting-gluing of spacetimes resolves the double-valuedness in the displacement vector D(E), pointed out by these…
We study the problem of existence of static spherically symmetric wormholes supported by the kink-like configuration of a scalar field. With this aim we consider a self-consistent, real, nonlinear, nonminimally coupled scalar field $\phi$…
Recent studies relating the approximations for the equations of state for thin shells and their consequent perturbative evolution are extended to thin-shell wormholes in theories beyond general relativity and more than four spacetime…
In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a thin shell surrounding…
The quartic self-interacting conformal scalar field is used to construct a thin-shell wormhole satisfying all energy conditions. Accompanying the scalar field is the extremal Reissner-Nordstr\"om black hole with a positive cosmological…
The static spherically symmetric thin shell of proper mass $m$ and electric charge $q$ around a central star or black hole of mass $M$ is in general unstable. Although with fine-tuned $m,q,$ and $M$ it can be considered quasi-stable. These…
Applying the Darmois-Israel thin shell formalism, we construct static and dynamic thin shells around traversable wormholes. Firstly, by applying the cut-and-paste technique we apply a linearized stability analysis to thin-shell wormholes in…
Wormholes have been always an interesting object in gravity theories. In this paper we make a little review of the principal properties of these objects and the exotic matter they need to exist. Then, we obtain two specific solutions in the…
The presented thesis is devoted to the study of instabilities of compact objects within the Einstein-Gauss-Bonnet theory. This theory includes higher-order corrections in curvature, which are inspired by the low energy limit of string…
Novel wormholes are obtained in Einstein-scalar-Gauss-Bonnet theory for several coupling functions. The wormholes may feature a single-throat or a double-throat geometry and do not demand any exotic matter. The scalar field may…
We cut a general, static, spherically symmetric spacetime and paste its copy to make a wormhole with a thin shell of any barotropic fluid in general relativity. We show that the stability of the thin-shell wormhole is characterized by a set…
We investigate the thin-shell wormholes constrained by cosmological observations for the first time in the literature. Without loss of generality, we study the thin-shell wormholes in $\omega$CDM model and analyze their stability under…
We consider Lorentzian wormholes with a phantom field and chiral matter fields. The chiral fields are described by the non-linear sigma model with or without a Skyrme term. When the gravitational coupling of the chiral fields is increased,…