Open AccessA Phantom Does Not Result from a Backreaction
Author(s) -
Hisako Tanaka,
Toshifumi Futamase
Publication year - 2007
Publication title -
progress of theoretical physics
Language(s) - English
Resource type - Journals
eISSN - 1347-4081
pISSN - 0033-068X
DOI - 10.1143/ptp.117.183
Subject(s) - physics , cosmological constant , equation of state , metric expansion of space , general relativity , phantom energy , constant (computer programming) , cosmic cancer database , dark energy , acceleration , nonlinear system , energy density , universe , quantum electrodynamics , classical mechanics , theoretical physics , cosmology , astrophysics , quantum mechanics , computer science , programming language
The backreaction of nonlinear inhomogeneities to the cosmic expansion isanalyzed in the framework of general relativity with a cosmological constant.By defining the spatially averaged matter energy density, we find that thecosmological constant induces a new type of backreaction whose equation ofstate is $p=-4/3 \rho$, where $\rho$ and $p$ are the effective energy densityand effective pressure of the backreaction in the averaged Friedmann universe.However, the effective density is negative, and thus it decreases theacceleration caused by the cosmological constant.Comment: 6pages, accepted by Progress of Theoretical Physic
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