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Title: Dynamical complexity of the Brans-Dicke cosmology

The dynamics of the Brans-Dicke theory with a quadratic scalar field potential function and barotropic matter is investigated. The dynamical system methods are used to reveal complexity of dynamical evolution in homogeneous and isotropic cosmological models. The structure of phase space crucially depends on the parameter of the theory ω{sub BD} as well as barotropic matter index w{sub m}. In our analysis these parameters are treated as bifurcation parameters. We found sets of values of these parameters which lead to generic evolutional scenarios. We show that in isotropic and homogeneous models in the Brans-Dicke theory with a quadratic potential function the de Sitter state appears naturally. Stability conditions of this state are fully investigated. It is shown that these models can explain accelerated expansion of the Universe without the assumption of the substantial form of dark matter and dark energy. The Poincare construction of compactified phase space with a circle at infinity is used to show that phase space trajectories in a physical region can be equipped with a structure of a vector field on nontrivial topological closed space. For ω{sub BD} < −3/2 we show new types of early and late time evolution leading from the anti-de Sitter tomore » the de Sitter state through an asymmetric bounce. In the theory without a ghost we find bouncing solutions and the coexistence of the bounces and the singularity. Following the Peixoto theorem some conclusions about structural stability are drawn.« less
Authors:
 [1] ;  [2]
  1. Theoretical Physics Division, National Centre for Nuclear Research, Hoża 69, 00-681 Warszawa (Poland)
  2. Astronomical Observatory, Jagiellonian University, Orla 171, 30-244 Kraków (Poland)
Publication Date:
OSTI Identifier:
22369872
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2013; Journal Issue: 12; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANTI DE SITTER GROUP; ANTI DE SITTER SPACE; ASYMMETRY; BIFURCATION; COMPACTIFICATION; COSMOLOGY; DE SITTER GROUP; DE SITTER SPACE; NONLUMINOUS MATTER; PHASE SPACE; SCALAR FIELDS; SINGULARITY; VECTOR FIELDS