Related papers: How much negative energy does a wormhole need?
A class of exact solutions of the Einstein field equations representing non-static wormholes that obey the {\em weak and dominant energy conditions } is presented. Hence, in principle, these wormholes can be built with less exotic matter…
In this talk I discuss pertinence of the wormholes to the problem of circumventing the light speed barrier and present a specific class of wormholes. The wormholes of this class are static and have arbitrarily wide throats, which makes them…
This essay reviews some of the recent progress in the area of energy conditions and wormholes. Most of the discussion centers on the subject of ``quantum inequality'' restrictions on negative energy. These are bounds on the magnitude and…
We provide a new matter source that supplies fuel to construct wormhole spacetime. The exact wormhole solutions are found in the model having, besides real matter, an anisotropic dark energy. We have shown that the exotic matters that are…
Within general relativity, we determine the energy conditions needed for the existence of a toroidal $T^2$ wormhole. For this purpose, we employ the conditions of the positiveness of the second derivatives of the relevant components of the…
Recently a bound on negative energy densities in four-dimensional Minkowski spacetime was derived for a minimally coupled, quantized, massless, scalar field in an arbitrary quantum state. The bound has the form of an uncertainty…
A new framework is proposed for general dynamic wormholes, unifying them with black holes. Both are generically defined locally by outer trapping horizons, temporal for wormholes and spatial or null for black and white holes. Thus wormhole…
We provide a 2-fluid immiscible matter source that supplies fuel to construct wormhole spacetime. The exact wormhole solutions are found in the model having, besides real matter or ordinary matter, some quintessence matter along with charge…
A wormhole is constructed by cutting and joining two spacetimes satisfying the low energy string equations with a dilaton field. In spacetimes described by the "string metric" the dilaton energy-momentum tensor need not satisfy the weak or…
For a generic $f(R)$ which admits a polynomial expansion of at least third order (i.e. $\frac{d^{3}f}{dR^{3}}\neq 0$) we find the near-throat wormhole solution. Necessary conditions for the existence of wormholes in such $f(R)$ theories are…
Firstly, we review the pointwise and averaged energy conditions, the quantum inequality and the notion of the ``volume integral quantifier'', which provides a measure of the ``total amount'' of energy condition violating matter. Secondly,…
Renormalized vacuum expectation values of electromagnetic stress-energy tensor are calculated in the background spherically-symmetrical metric of the wormhole's topology. Covariant geodesic point separation method of regularization is used.…
We present the first analysis of traversable wormhole solutions within the framework of Einstein-aether theory. We show that the corresponding field equations admit three distinct wormhole geometries, obtained by adopting three different…
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…
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…
Traversible wormhole space-times are found as static, spherically symmetric solutions to the Einstein equations with ingoing and outgoing pure ghost radiation, i.e. pure radiation with negative energy density. Switching off the radiation…
A class of wormhole solutions is constructed that has restricted polar degrees of freedom to achieve a gateway-like configuration. This compels the use of distribution-valued metrics and connections which further compels the use of neutrix…
We obtain a large class of Lorentzian wormhole spacetimes in scalar-tensor gravity, for which the matter stress energy does satisfy the weak energy condition. Our constructions have zero Ricci scalar and an everywhere finite, non-zero…
We considered the generation of gravitational waves by the binary system associated with a wormhole. In the Newtonian limit, the gravitational potential of a wormhole requires the effective mass of the wormhole taking into account radial…