Model-independent dark energy differentiation with the ISW effect
Abstract
We study the integrated Sachs-Wolfe (ISW) effect using a model-independent parameterization of the dark energy equation of state. Cosmic variance severely restricts the class of models distinguishable from Lambda-CDM. In particular if the present value of the equation of state satisfies w_Q^o <-0.8, the only distinguishable models are those with a rapidly varying equation of state, characterized by a late transition occurring at redshifts z<3. Due to the degeneracy with other cosmological parameters, models with a slowly varying behavior cannot be differentiated from each other or from a cosmological constant using even cosmic variance-limited CMB measurements. This may place a fundamental limit on our understanding of the origin of the presently observed acceleration.
Cite
@article{arxiv.astro-ph/0210209,
title = {Model-independent dark energy differentiation with the ISW effect},
author = {P. S. Corasaniti and B. A. Bassett and C. Ungarelli and E. J. Copeland},
journal= {arXiv preprint arXiv:astro-ph/0210209},
year = {2009}
}
Comments
5 pages, 5 figures