Wormholes supported by phantom-like modified Chaplygin gas

We have examined the possible construction of a stationary, spherically symmetric and spatially inhomogeneous wormhole spacetime supported by the phantom energy. The latter is supposed to be represented by the modified Chaplygin gas equation of state. The solutions so obtained satisfy the flare-out and the asymptotic-flatness conditions. It is also shown that the averaged null-energy condition has to be violated for the existence of the wormhole.     

A single model of traversable wormholes supported by generalized phantom energy or Chaplygin gas

This paper discusses a new variable equation of state parameter leading to exact solutions of the Einstein field equations describing traversable wormholes. In addition to generalizing the notion of phantom energy, the equation of state generates a mathematical model that combines the generalized phantom energy and the generalized Chaplygin gas models.     

Stringy Wormholes

The possibility of static wormhole solutions in the string modified gravity is examined. It turns out that practically traversable wormholes are not available in the two types of solutions considered. Interestingly, these two solutions display exactly opposite wormhole features.     

Quintom Wormholes

The combination of quintessence and phantom energy in a joint model is referred to as quintom dark energy. This paper discusses traversable wormholes supported by such quintom matter. Two particular solutions are explored, a constant redshift function and a specific shape function. Both isotropic and anisotropic pressures are considered.     

Wormhole supported by dark energy admitting conformal motion

In this article, we study the possibility of sustaining static and spherically symmetric traversable wormhole geometries admitting conformal motion in Einstein gravity, which presents a more systematic approach to search a relation between matter and geometry. In wormhole physics, the presence of exotic matter is a fundamental ingredient and we show that this exotic source can be dark energy type which support the existence of wormhole spacetimes. In this work we model a wormhole supported by dark energy which admits conformal motion. We also discuss the possibility of the detection of wormholes in the outer regions of galactic halos by means of gravitational lensing. Studies of the total gravitational energy for the exotic matter inside a static wormhole configuration are also performed.     

Creation/annihilation of wormholes supported by the Sine-Gordon phantom (ghost) field

The possible process of creation/annihilation of traversable wormholes in the model with phantom (ghost) scalar field is described. It is shown that such process can be realized only for some special choice of a potential energy, in particular, for the Sine-Gordon potential.     

Exact solution of phantom dark energy model

We investigate the phantom dark energy model derived from the scalar field with a negative kinetic term.By assuming a particular relation between the time derivative of the phantom field and the Hubble function,an exact solution of the model is constructed.Absence of the ’big rip’ singularity is shown explicitly.We then derive special features of phantom dark energy model and show that its predictions are consistent with all astrophysical observations.     

Wormholes in dilatonic Einstein-Gauss-Bonnet theory

We construct traversable wormholes in dilatonic Einstein-Gauss-Bonnet theory in four spacetime dimensions, without needing any form of exotic matter. We determine their domain of existence, and show that these wormholes satisfy a generalized Smarr relation. We demonstrate linear stability with respect to radial perturbations for a subset of these wormholes.     

Wormholes in vacuum Brans-Dicke theory

We present a Euclidean wormhole solution in vacuum Brans-Dicke theory, which is different from that obtained by Accetta et al. This wormhole appears to have the feature that its throat dimension increases linearly with Euclidean cosmic time, although this increase may not be measurable. It also requires a negative Brans-Dicke parameter.     

On the accretion of phantom energy onto wormholes

By using a properly generalized accretion formalism it is argued that the accretion of phantom energy onto a wormhole does not make the size of the wormhole throat to comovingly scale with the scale factor of the universe, but instead induces an increase of that size so big that the wormhole can engulf the universe itself before it reaches the big rip singularity, at least relative to an asymptotic observer.