GT5 - Wormholes, Energy Conditions and Time Machines |
Speaker_ |
Lobo, Francisco |
Talk _ |
Traversable wormholes supported by cosmic accelerated expanding equations of state |
Abstract _ |
We shall explore the possibility that traversable wormholes be supported by specific equations of state responsible for the present accelerated expansion of the Universe, namely phantom energy, the generalized Chaplygin gas, and the van der Waals quintessence equation of state. Firstly, phantom energy possesses an equation of state of the form $\omega\equiv p/\rho<-1$, consequently violating the null energy condition. As this is the fundamental ingredient to sustain traversable wormholes, this cosmic fluid presents us with a natural scenario for the existence of these exotic geometries. In this context, we investigate the physical properties and characteristics of these phantom energy traversable wormholes. Secondly, the generalized Chaplygin gas (GCG) is a candidate for the unification of dark energy and dark matter, and is parametrized by an exotic equation of state given by $p_{ch}=-A/\rho_{ch}^{\alpha}$, where $A$ is a positive constant and $0<\alpha \leq 1$. In this context, we shall explore exact solutions of spherically symmetric traversable wormholes supported by the GCG. Thirdly, the van der Waals quintessence equation of state is an interesting scenario for describing the late universe, and seems to provide a solution to the puzzle of dark energy, without the presence of exotic fluids or modifications of the Friedmann equations. Solutions of traversable wormholes where the exotic matter is constrained to the throat neighborhood, as well as an exact solution of an asymptotically flat wormhole, are found. |