2008/06/30 by James B. Dent, Sourish Dutta, T. Weiler +1
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1103/physrevd.79.023502
published as Phys.Rev.D79:023502,2009 · Accepted for publication at PRD
arxiv created 2008/12/09 · openalex publication_date 2009/01/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The effect of quintessence perturbations on the integrated Sachs-Wolfe (ISW) effect is studied for a mixed dynamical scalar field dark energy (DDE) and pressureless perfect fluid dark matter. A new and general methodology is developed to track the growth of the perturbations, which uses only the equation of state (EoS) parameter wDDE(z)\ensuremath≡pDDE/\ensuremathρDDE of the scalar field DDE, and the initial values of the relative entropy perturbation (between the matter and DDE) and the intrinsic entropy perturbation of the scalar field DDE as inputs. We also derive a relation between the rest-frame sound speed \stackrel^cs,DDE2 of an arbitrary scalar field DDE component and its EoS wDDE(z). We show that the ISW signal differs from that expected in a \ensuremathΛCDM cosmology by as much as +20% to \ensuremath-80% for parametrizations of wDDE consistent with SNIa data, and about \ifmmode±\else\textpm\fi20% for parametrizations of wDDE consistent with SNIa+CMB+BAO data, at 95% confidence. Our results indicate that, at least in principle, the ISW effect can be used to phenomenologically distinguish a cosmological constant from DDE.