Effects of Inhomogeneities on Cosmic Expansion
نویسنده
چکیده
We evaluate the effect of inhomogeneity energy on the expansion rate of the universe. Our method is to expand to Newtonian order in potential and velocity but to take into account fully nonlinear density inhomogeneities. To linear order in density, kinetic and gravitational potential energy contribute to the total energy of the universe with the same scaling with expansion factor as spatial curvature. In the strongly nonlinear regime, growth saturates, and the net effect of the inhomogeneity energy on the expansion rate remains negligible at all times. In particular, inhomogeneity contributions never mimic the effects of dark energy or induce an accelerated expansion. Subject headings: cosmological parameters — cosmology : theory — large-scale structure of universe
منابع مشابه
Apparent Acceleration through Large-scale Inhomogeneities Post-Friedmannian Effects of Inhomogeneities on the Luminosity Distance
We re-analyze the observed magnitude-redshift relation of type Ia supernovae (SNe Ia) and examine the possibility that the apparent acceleration of the cosmic expansion is not caused by dark energy but is instead a consequence of the large-scale inhomogeneities in the universe. We propose a method to phenomenologically describe the effects of the large-scale inhomogeneities without relying on t...
متن کاملApparent Acceleration through the Large-scale Inhomogeneities Post-Friedmannian effects of inhomogeneities on the luminosity distance
We re-analyze the observed magnitude-redshift relation of type Ia supernovae (SNe Ia) and examine the possibility that the apparent acceleration of the cosmic expansion is not caused by dark energy, but is a consequence of large-scale inhomogeneities in the universe. We propose a method to describe phenomenologically the effects of the large-scale inhomogeneities, without depending on the speci...
متن کاملGravitational backreaction in cosmological spacetimes
We develop a new formalism for the treatment of gravitational backreaction in the cosmological setting. The approach is inspired by projective techniques in non-equilibrium statistical mechanics. We employ group-averaging with respect to the action of the isotropy group of homogeneous and isotropic spacetimes (rather than spatial averaging), in order to define effective FRW variables for a gene...
متن کاملar X iv : a st ro - p h / 05 06 44 9 v 3 9 J un 2 00 6 Can a dust dominated universe have accelerated expansion ?
Recently, there has been suggestions that the apparent accelerated expansion of the universe is due not to a cosmological constant, but rather to inhomogeneities in the distribution of matter. In this work, we investigate a specific class of inhomogeneous models that can be solved analytically, namely the dust-dominated Lemâitre-Tolman-Bondi universe models. We show that they do not permit acce...
متن کاملar X iv : a st ro - p h / 05 06 44 9 v 4 1 9 Ju n 20 06 Can a dust dominated universe have accelerated expansion ?
Recently, there has been suggestions that the apparent accelerated expansion of the universe is due not to a cosmological constant, but rather to inhomogeneities in the distribution of matter. In this work, we investigate a specific class of inhomogeneous models that can be solved analytically, namely the dust-dominated Lemâitre-Tolman-Bondi universe models. We show that they do not permit acce...
متن کامل