Inhomogeneities in dusty universe - a possible alternative to dark energy?

Abstract

There have been of late renewed debates on the role of inhomogeneities to explain the observed late acceleration of the universe. We have looked into the problem analytically with the help of the well known spherically symmetric but inhomogeneous Lemaitre-Tolman-Bondi(LTB) model generalised to higher dimensions. It is observed that in contrast to the claim made by Kolb et al the presence of inhomogeneities as well as extra dimensions can not reverse the signature of the deceleration parameter if the matter field obeys the energy conditions. The well known Raychaudhuri equation also points to the same result. Without solving the field equations explicitly it can, however, be shown that although the total deceleration is positive everywhere nevertheless it does not exclude the possibility of having radial acceleration, even in the pure dust universe, if the angular scale factor is decelerating fast enough and vice versa. Moreover it is found that introduction of extra dimensions can not reverse the scenario. To the contrary it actually helps the decelerating process.

arXiv comment14 pages, 4 figures

References in corpus (23)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Dynamics of dark energy
• Is cosmic acceleration slowing down?
• Accelerated expansion from structure formation
• The effect of inhomogeneous expansion on the supernova observations
• Is dark energy the only solution to the apparent acceleration of the present universe?
• Mimicking Dark Energy with Lemaitre-Tolman-Bondi Models: Weak Central Singularities and Critical Points
• Can superhorizon cosmological perturbations explain the acceleration of the universe?
• Late-time Inhomogeneity and Acceleration Without Dark Energy
• Super-Hubble Nonlinear Perturbations During Inflation
• Solving the Inverse Problem with Inhomogeneous Universes
• Testing the Copernican Principle via Cosmological Observations
• Cosmic acceleration: Inhomogeneity versus vacuum energy
• Imitating accelerated expansion of the Universe by matter inhomogeneities - corrections of some misunderstandings
• Anisotropic Observations in Universes with Nonlinear Inhomogeneity
• Can a dust dominated universe have accelerated expansion?
• Inhomogeneous dusty Universes and their deceleration
• Accelerating universe from warped extra dimensions
• An expanding 4D universe in a 5D Kaluza-Klein cosmology with higher dimensional matter
• Quintessential Phenomena in Higher Dimensional Space Time
• The warping of extra spaces accelerates the expansion of the universe
• Accelerating Universe from an Evolving Lambda in Higher Dimension

Cited by in corpus (7)

• Cosmological and Solar System Consequences of f(R,T) Gravity Models
• Establishing homogeneity of the universe in the shadow of dark energy
• Measurement of marked correlation functions in SDSS-III Baryon Oscillation Spectroscopic Survey using LOWZ galaxies in Data Release 12
• Thermodynamics of the Variable Modified Chaplygin gas
• Spherically symmetric inhomogeneous model with Chaplygin gas
• Low red-shift effects of local structure on the Hubble parameter in presence of a cosmological constant
• An Alternative Approach to the Exact Solution of FRW-Type Spacetime with a Generalized Chaplygin Gas