Related papers: Field Sources for Generalized Ellis-Bronnikov Worm…
The Ellis wormhole is known to be an exact solution of the Einstein--scalar system where the scalar field has negative kinetic energy (phantom). We show here that the same geometry (in 3+1 dimensions) can also be obtained with `tachyon…
We study the shear viscosity to entropy ratio $\eta/S$ in the boundary field theories dual to black hole backgrounds in theories of gravity coupled to a scalar field, and generalisations including a Maxwell field and non-minimal scalar…
Wormholes are interesting space-time structures connecting two asymptotic regions found in a universe or multiverse and are solutions to Einstein's field equations. These objects have many interesting features as far as physics is…
Traditionally, the embedding procedure for spherically symmetric spacetimes has been restricted to the equatorial plane $\theta = \pi/2$. This conventional approach, however, encounters a fundamental limitation: not every spherically…
Wormholes are speculative structures linking disparate space-time points. Their geometry can be obtained by solving Einstein equations with tolerating the violation of null energy conditions. Recently, many researchers have studied…
Embedding theorems, which have a long history in the general theory of relativity, are used in this paper to account for two of the most troubling aspects of Morris-Thorne wormholes, (1) the origin of exotic matter and the amount needed to…
In 6D general relativity with a scalar field as a source of gravity, a new type of static wormhole solutions is presented: such wormholes connect our universe with a small 2D extra subspace with a universe where this extra subspace is…
The present study analyses the wormhole solution both in the dRGT-$ f(R,T) $ massive gravity and Einstein massive gravity. In both the models, the anisotropic pressure solution in ultrastatic wormhole geometry gives rise to the shape…
We numerically investigate the dynamical evolution of spherically symmetric charge free wormholes. We concentrate on two specific examples, both of which exhibit wormhole expansion and wormhole collapse: the Ellis-Bronnikov wormhole, which…
We study static traversable wormholes obtained by Morris and Thorne in general relativity (GR) in the framework of a modified theory of gravity. The modified gravitational action $f(R,T)$ is a function of the Ricci scalar ($R$) and of the…
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,…
We consider the construction of generic spherically symmetric thin-shell traversable wormhole spacetimes in standard general relativity. By using the cut-and-paste procedure, we comprehensively analyze the stability of arbitrary spherically…
In this paper, we present new generalized wormhole (WH) solutions within the context of $f(R)$ gravity. Specifically, we focus on $f(R)$ gravitational theories formulated in the metric formalism, with our investigation centered on a…
We investigate the observable signatures -- the shadow, the throat silhouette, and the image of a thin accretion disk -- for a family of static, spherically symmetric wormholes with an arbitrary throat profile. First, we derive expressions…
We discuss $(n+1)$-dimensional dynamical wormholes in an evolving cosmological background with a throat expanding with time. These solutions are examined in the general relativity framework. A linear relation between diagonal elements of an…
Recently, there has been significant interest regarding the regularization of a $D\rightarrow 4$ limit of Einstein-Gauss-Bonnet (EGB) gravity. This regularization involves re-scaling the Gauss-Bonnet (GB) coupling constant as…
Spacetime wormholes in isotropic spacetimes are represented traditionally by embedding diagrams which were symmetric paraboloids. This mirror symmetry, however, can be broken by considering different sources on different sides of the…
Wormhole solutions in a generalized hybrid metric-Palatini matter theory, given by a gravitational Lagrangian $f\left(R,\cal{R}\right)$, where $R$ is the metric Ricci scalar, and $\mathcal{R}$ is a Palatini scalar curvature defined in terms…
The general parametrization for spacetimes of spherically symmetric Lorentzian, traversable wormholes in an arbitrary metric theory of gravity is presented. The parametrization is similar in spirit to the post-Newtonian parametrized…
The well-known problem of wormholes in general relativity (GR) is the necessity of exotic matter, violating the Weak Energy Condition (WEC), for their support. This problem looks easier if, instead of island-like configurations, one…