UNIFIED PHANTOM COSMOLOGIES
نویسندگان
چکیده
منابع مشابه
Unified phantom cosmologies
We present a general algorithm based on the concept of forminvariance which can be used for generating phantom cosmologies. It involves linear transformations between the kinetic energy and the potential of the scalar field, and transforms solutions of the EinsteinKlein-Gordon equations which preserve the weak energy condition into others which violate it, while keeping the energy density of th...
متن کاملObservational constraints on phantom-like braneworld cosmologies
We investigate a simple braneworld model in which the universe contains only cold dark matter and a cosmological constant, but the effective dark energy is phantom-like because of extra-dimensional gravity effects. Modified gravity screens the cosmological constant Λ, allowing for a larger Λ. In practice, observations do not favour any significant screening. We use supernova data, the cosmic mi...
متن کاملCoupled oscillators as models of phantom and scalar field cosmologies
We study a toy model for phantom cosmology recently introduced in the literature and consisting of two oscillators, one of which carries negative kinetic energy. The results are compared with the exact phase space picture obtained for similar dynamical systems describing, respectively, a massive canonical scalar field conformally coupled to the spacetime curvature, and a conformally coupled mas...
متن کاملA Unified Model of Phantom Energy and Dark Matter
To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys w = p/ρ < −1/3. This form of massenergy leads to accelerated expansion. An extreme form of dark energy, called phantom energy, has been proposed which has w = p/ρ < −1. This possibil...
متن کاملEvolution of a Schwarzschild Black Hole in Phantom-like Chaplygin gas Cosmologies
In the classical relativistic regime, the accretion of phantom energy onto a black hole reduces the mass of the black hole. In this context, we have investigated the evolution of a Schwarzschild black hole in the standard model of cosmology using the phantom-like modified variable Chaplygin gas and the viscous generalized Chaplygin gas. The corresponding expressions for accretion time scale and...
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ژورنال
عنوان ژورنال: International Journal of Modern Physics D
سال: 2005
ISSN: 0218-2718,1793-6594
DOI: 10.1142/s021827180500616x