Non-homogeneity-driven Universe acceleration

Abstract

Class of spherically symmetric Stephani cosmological models is examined in the context of evolution type. It is assumed that the equation of state at the symmetry center of the models is barotropic. Classification of cosmological models is performed depending on different values and signs of two free parameters. It is shown that for (hyperbolic geometry) dust-like cosmological model exhibits accelerated expansion at later stages of evolution. The Hubble and deceleration parameters are defined in the model and it is shown that the deceleration parameter decreases with the distance becoming negative for sufficiently distant galaxies. Redshift-magnitude relation is calculated and discussed in the context of SnIa observational data. It is noticed that the most distant supernovae of type Ia fit quite well to the redshift-magnitude relation calculated in the considered model without introducing the cosmological constant. It is also shown that the age of the universe in the model is longer than in the Friedmann model corresponding to the same Hubble and energy density parameters.

21 pages, 7 figures, corrected version of the paper published in Class. Quantum Grav. 18 (2001) 2643-2658

References in corpus (8)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Cosmological Imprint of an Energy Component with General Equation of State
• The Absolute Luminosities of the Calan/Tololo Type Ia Supernovae
• A Low-Density Closed Universe
• Undermining the Cosmological Principle: Almost Isotropic Observations in Inhomogeneous Cosmologies
• The Hubble Diagram of Type Ia Supernovae in Non-Uniform Pressure Universes
• A Redshift-Magnitude Relation for Non-Uniform Pressure Universes
• Towards a physical interpretation for the Stephani Universes

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• Quantum Stephani exact cosmological solutions and the selection of time variable
• The Averaging Problem in Cosmology
• Noncommutative Corrections to the Robertson-Walker metric
• A critical assessment of some inhomogeneous pressure Stephani models
• Creatable Universes
• Thermodynamics of Shearing Massless Scalar Field Spacetimes is Inconsistent With the Weyl Curvature Hypothesis
• Modelling spatial variations of the speed of light
• Accelerated Expansion of the Universe in the Model with Non-Uniform Pressure
• Quantum Stephani Universe in vicinity of the symmetry center
• Dark side of the universe in the Stephani cosmology
• Analytical solutions for two inhomogeneous cosmological models with energy flow and dynamical curvature
• Stephani Cosmology: Entropically Viable But Observationally Challenged
• Off-center observers versus supernovae in inhomogeneous pressure universes
• Accelerated expansion of the universe from the perspective of inhomogeneous cosmology
• Holographic Principle and the Second Law in Stephani Cosmology Revisited