Related papers: Noncommutative-geometry wormholes based on the Cas…
We explore the possibility of dynamic wormhole geometries, within the context of nonlinear electrodynamics. The Einstein field equation imposes a contracting wormhole solution and the obedience of the weak energy condition. Furthermore, in…
A Morris-Thorne wormhole can only be sustained by violating the null energy condition, thereby requiring the existence of "exotic matter," a requirement that many researchers consider unphysical. Using a mostly qualitative approach, it is…
It is well known that solutions of general relativity which allow for traversable wormholes require the existence of exotic matter (matter that violates weak or null energy conditions [WEC or NEC]). In this article, we provide a class of…
Ghost stars are compact configurations characterized by an arbitrarily small total mass. Such objects require regions of negative energy density -a condition typically regarded as unphysical within the context of conventional stellar…
We analyze the static and spherically symmetric perfect fluid solutions of Einstein field equations inspired by the non commutative geometry. In the framework of the non commutative geometry this solution is interpreted as a mini black hole…
The existence of irreducible field fluctuations in vacuum is an important prediction of quantum theory. These fluctuations have many observable consequences, like the Casimir effect which is now measured with good accuracy and agreement…
The discussion of vacuum energy is currently a subject of great theoretical importance, specially concerning the cosmological constant problem in General Relativity. From Quantum Field Theory, it is stated that vacuum states subject to…
The static spherically symmetric traversable wormholes are analysed in the Einstein- Cartan theory of gravitation. In particular, we computed the torsion tensor for matter fields with different spin S = 0; 1/2; 1; 3/2. Interestingly, only…
We present new traversable wormhole and non-singular black hole solutions in pure, scale-free $R^2$ gravity. These exotic solutions require no null energy condition violating or "exotic" matter and are supported only by the vacuum of the…
First, the ideas introduced in the wormhole research field since the work of Morris and Thorne are briefly reviewed, namely, the issues of energy conditions, wormhole construction, stability, time machines and astrophysical signatures.…
The Casimir effect refers to the existence of a macroscopic force between conducting plates in vacuum due to quantum fluctuations of fields. These forces play an important role, among other things, in the design of nano-scale mechanical…
In this paper, we construct models that admit the traversable wormhole geometries in the framework of Einstein's gravity with two scalar fields. As well known, the energy conditions are broken and we show that there appears a ghost. The…
We present a static, spherically symmetric, traversable wormhole solution to multimetric gravity which is sustained by only non-exotic matter, i.e., matter which satisfies all energy conditions. The possibility of this solution arises from…
The Casimir effect, which predicts the emergence of an attractive force between two parallel, highly reflecting plates in vacuum, plays a vital role in various fields of physics, from quantum field theory and cosmology to nanophotonics and…
Casimir energy is always suggested as a possible source to create a traversable wormhole. It is also used to demonstrate the existence of negative energy, which can be created in a lab. To generalize, this idea, Yukawa modification of…
Non-commutativity is a key feature of spacetime geometry. The current article explores the traversable wormhole solutions in the framework of $f(R,L_m)$ gravity within non-commutative geometry. By using the Gaussian and Lorentzian…
We construct wormholes in Einstein-vector-Gauss-Bonnet theory where a real massless vector field is coupled to the higher curvature Gauss-Bonnet invariant. We consider three coupling functions which depend on the square of the vector field.…
In [J. Blazquez-Salcedo, C. Knoll, E. Radu, Phys. Rev. Lett. 126 (2021) no.10, 101102] asymptotically flat traversable wormhole solutions were obtained in the Einstein-Dirac-Maxwell theory without using phantom matter. The normalizable…
When Morris and Thorne first proposed the possible existence of traversable wormholes, they adopted the following strategy: maintain complete control over the geometry, thereby leaving open the determination of the stress-energy tensor. In…
It is generally agreed that the acceleration of the Universe can best be explained by the presence of dark or phantom energy. The equation of state of the latter shows that the null energy condition is violated. Such a violation is the…