ar X iv : g r - qc / 0 50 30 05 v 1 1 M ar 2 00 5 Dark energy , wormholes , and the Big Rip
نویسندگان
چکیده
The time evolution of a wormhole in a Friedmann universe approaching the Big Rip is studied. The wormhole is modeled by a thin spherical shell accreting the superquintessence fluid – two different models are presented. Contrary to recent claims that the wormhole overtakes the expansion of the universe and engulfs it before the Big Rip is reached, it is found that the wormhole becomes asymptotically comoving with the cosmic fluid and the future evolution of the universe is fully causal.
منابع مشابه
ar X iv : g r - qc / 0 50 30 97 v 2 2 7 M ar 2 00 5 SU
Wormholes have been advanced as both a method for circumventing the limitations of the speed of light as well as a means for building a time machine (to travel to the past). Thus it is argued that General Relativity may allow both of these possibilities. In this note I argue that traversable wormholes connecting otherwise causally disconnected regions, violate two of the most fundamental princi...
متن کاملar X iv : g r - qc / 0 40 50 20 v 1 5 M ay 2 00 4 On big rip singularities
In this comment we discuss big rip singularities occurring in typical phantom models by violation of the weak energy condition. After that, we compare them with future late-time singularities arising in models where the scale factor ends in a constant value and there is no violation of the strong energy condition. In phantom models the equation of state is well defined along the whole evolution...
متن کاملar X iv : g r - qc / 0 60 90 76 v 2 1 5 N ov 2 00 6 Thermodynamics second law and ω = − 1 crossing ( s ) in interacting holographic dark energy model
Thermodynamics second law and ω = −1 crossing(s) in interacting holographic dark energy model Abstract By the assumption that the thermodynamics second law is valid, we study the possibility of ω = −1 crossing in an interacting holographic dark energy model. Depending on the choice of the horizon and the interaction, the transition from quintessence to phantom regime and subsequently from phant...
متن کاملar X iv : g r - qc / 0 40 30 62 v 1 1 5 M ar 2 00 4 The Chaplygin gas as a model for dark energy
We review the essential features of the Chaplygin gas cosmological models and provide some examples of appearance of the Chaplygin gas equation of state in modern physics. A possible theoretical basis for the Chaplygin gas in cosmology is discussed. The relation with scalar field and tachyon cosmological models is also considered.
متن کاملar X iv : g r - qc / 0 70 10 32 v 3 2 8 O ct 2 00 8 Wormholes with varying equation of state parameter
We propose wormholes solutions by assuming space dependent equation of state parameter. Our models show that the existence of wormholes is supported by phantom energy. Here, the phantom energy is characterized by variable equation state parameter. We show that the averaged null energy condition (ANEC) violating phantom energy can be reduced as desired.
متن کامل