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Title: Tracking dark energy with the integrated Sachs-Wolfe effect: Short and long-term predictions

Abstract

We present an analysis of the constraining power of future measurements of the integrated Sachs-Wolfe (ISW) effect on models of the equation of state of dark energy as a function of redshift, w(z). To achieve this, we employ a new parametrization of w, which utilizes the mean value of w(z) (<w>) as an explicit parameter. This helps to separate the information contained in the estimation of the distance to the last scattering surface (from the cosmic microwave background (CMB)) from the information contained in the ISW effect. We then use Fisher analysis to forecast the expected uncertainties in the measured parameters from future ISW observations for two models of dark energy with very different time evolution properties. For example, we demonstrate that the cross correlation of Planck CMB data and large synoptic survey telescope (LSST) galaxy catalogs will provide competitive constraints on w(z), compared to a supernovae acceleration probe (SNAP)-like supernovae (SNe) project, for models of dark energy with a rapidly changing equation of state (e.g. Kink models). Our work confirms that, while SNe measurements are more suitable for constraining variations in w(z) at low redshift, the ISW effect can provide important independent constraints on w(z) at high z.

Authors:
;  [1];  [2]; ;  [3]
  1. Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States)
  2. ISCAP, Columbia University, New York, New York 10027 (United States)
  3. ICG, University of Portsmouth, Portsmouth, PO1 2EG (United Kingdom)
Publication Date:
OSTI Identifier:
20711546
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 72; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevD.72.103519; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CORRELATIONS; COSMIC RADIATION; COSMOLOGY; EQUATIONS OF STATE; GALAXIES; NONLUMINOUS MATTER; RADIOWAVE RADIATION; RED SHIFT; RELICT RADIATION; SUPERNOVAE; SURFACES

Citation Formats

Pogosian, Levon, Stephan-Otto, Christian, Corasaniti, Pier Stefano, Crittenden, Robert, and Nichol, Robert. Tracking dark energy with the integrated Sachs-Wolfe effect: Short and long-term predictions. United States: N. p., 2005. Web. doi:10.1103/PhysRevD.72.103519.
Pogosian, Levon, Stephan-Otto, Christian, Corasaniti, Pier Stefano, Crittenden, Robert, & Nichol, Robert. Tracking dark energy with the integrated Sachs-Wolfe effect: Short and long-term predictions. United States. doi:10.1103/PhysRevD.72.103519.
Pogosian, Levon, Stephan-Otto, Christian, Corasaniti, Pier Stefano, Crittenden, Robert, and Nichol, Robert. Tue . "Tracking dark energy with the integrated Sachs-Wolfe effect: Short and long-term predictions". United States. doi:10.1103/PhysRevD.72.103519.
@article{osti_20711546,
title = {Tracking dark energy with the integrated Sachs-Wolfe effect: Short and long-term predictions},
author = {Pogosian, Levon and Stephan-Otto, Christian and Corasaniti, Pier Stefano and Crittenden, Robert and Nichol, Robert},
abstractNote = {We present an analysis of the constraining power of future measurements of the integrated Sachs-Wolfe (ISW) effect on models of the equation of state of dark energy as a function of redshift, w(z). To achieve this, we employ a new parametrization of w, which utilizes the mean value of w(z) (<w>) as an explicit parameter. This helps to separate the information contained in the estimation of the distance to the last scattering surface (from the cosmic microwave background (CMB)) from the information contained in the ISW effect. We then use Fisher analysis to forecast the expected uncertainties in the measured parameters from future ISW observations for two models of dark energy with very different time evolution properties. For example, we demonstrate that the cross correlation of Planck CMB data and large synoptic survey telescope (LSST) galaxy catalogs will provide competitive constraints on w(z), compared to a supernovae acceleration probe (SNAP)-like supernovae (SNe) project, for models of dark energy with a rapidly changing equation of state (e.g. Kink models). Our work confirms that, while SNe measurements are more suitable for constraining variations in w(z) at low redshift, the ISW effect can provide important independent constraints on w(z) at high z.},
doi = {10.1103/PhysRevD.72.103519},
journal = {Physical Review. D, Particles Fields},
number = 10,
volume = 72,
place = {United States},
year = {Tue Nov 15 00:00:00 EST 2005},
month = {Tue Nov 15 00:00:00 EST 2005}
}
  • I discuss several issues that arise when trying to constrain the dark energy equation of state using correlations of the integrated Sachs-Wolfe effect with galaxy counts and lensing of the cosmic microwave background. These techniques are complementary to others such as galaxy shear surveys, and can use data that will already be obtained from currently planned observations. In regimes where cosmic variance and shot noise are the dominant sources of error, constraints could be made on the mean equation of state to {+-}0.33 and its first derivative to {+-}1.0. Perhaps more interesting is that the determination of dark energy parametersmore » by these types of experiments depends strongly on the presence or absence of perturbations in the dark energy fluid.« less
  • We cross correlate the new 3 year Wilkinson Microwave Anistropy Probe (WMAP) cosmic microwave background data with the NRAO VLA Sky Survey radio galaxy data and find further evidence of late integrated Sachs-Wolfe (ISW) effect taking place at late times in cosmic history. Our detection makes use of a novel statistical method (P. Baldi, G. Kerkyacharian, D. Marinucci, and D. Picard, math.ST/0606154 and P. Baldi, G. Kerkyacharian, D. Marinucci, D. Picard, math.ST/0606599) based on a new construction of spherical wavelets, called needlets. The null hypothesis (no ISW) is excluded at more than 99.7% confidence. When we compare the measured crossmore » correlation with the theoretical predictions of standard, flat cosmological models with a generalized dark energy component parameterized by its density, {omega}{sub DE}, equation of state w and speed of sound c{sub s}{sup 2}, we find 0.3{<=}{omega}{sub DE}{<=}0.8 at 95% C.L., independently of c{sub s}{sup 2} and w. If dark energy is assumed to be a cosmological constant (w=-1), the bound on density shrinks to 0.41{<=}{omega}{sub DE}{<=}0.79. Models without dark energy are excluded at more than 4{sigma}. The bounds on w depend rather strongly on the assumed value of c{sub s}{sup 2}. We find that models with more negative equation of state (such as phantom models) are a worse fit to the data in the case c{sub s}{sup 2}=1 than in the case c{sub s}{sup 2}=0.« less
  • Models with dark energy decaying into dark matter have been proposed in cosmology to solve the coincidence problem. We study the effect of such coupling on the cosmic microwave background temperature anisotropies. The interaction changes the rate of evolution of the metric potentials and the growth rate of matter density perturbations and modifies the integrated Sachs-Wolfe component of cosmic microwave background temperature anisotropies, enhancing the effect. Cross correlation of galaxy catalogs with cosmic microwave background maps provides a model-independent test to constrain the interaction. We particularize our analysis for a specific interacting model and show that galaxy catalogs with medianmore » redshifts z{sub m}=0.1-0.9 can rule out models with an interaction parameter strength of c{sup 2}{approx_equal}0.1 better than 99.95% confidence level. Values of c{sup 2}{<=}0.01 are compatible with the data and may account for the possible discrepancy between the fraction of dark energy derived from Wilkinson microwave anisotropy probe 3 yr data and the fraction obtained from the integrated Sachs-Wolfe effect. Measuring the fraction of dark energy by these two methods could provide evidence of an interaction.« less
  • 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 w{sub DDE}(z){identical_to}p{sub DDE}/{rho}{sub DDE} 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 c-circumflex{sub s,DDE}{sup 2} ofmore » an arbitrary scalar field DDE component and its EoS w{sub DDE}(z). We show that the ISW signal differs from that expected in a {lambda}CDM cosmology by as much as +20% to -80% for parametrizations of w{sub DDE} consistent with SNIa data, and about {+-}20% for parametrizations of w{sub DDE} 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.« less
  • In this paper, we investigate the integrated Sachs-Wolfe effect in the quintessence cold dark matter model with constant equation of state and constant speed of sound in dark energy rest frame, including dark energy perturbation and its anisotropic stress. Comparing with the {Lambda}CDM model, we find that the integrated Sachs-Wolfe (ISW)-power spectrums are affected by different background evolutions and dark energy perturbation. As we change the speed of sound from 1 to 0 in the quintessence cold dark matter model with given state parameters, it is found that the inclusion of dark energy anisotropic stress makes the variation of magnitudemore » of the ISW source uncertain due to the anticorrelation between the speed of sound and the ratio of dark energy density perturbation contrast to dark matter density perturbation contrast in the ISW-source term. Thus, the magnitude of the ISW-source term is governed by the competition between the alterant multiple of (1+3/2xc-circumflex{sub s}{sup 2}) and that of {delta}{sub de}/{delta}{sub m} with the variation of c-circumflex{sub s}{sup 2}.« less