New perspective on the relation between dark energy perturbations and the late-time integrated Sachs-Wolfe effect

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.023502· OSTI ID:21259775

Dent, James B; Dutta, Sourish; Weiler, Thomas J ^[1]

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1. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

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} of 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.

• OSTI ID: 21259775
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 2 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COSMOLOGICAL CONSTANT
COSMOLOGY
DISTURBANCES
ENTROPY
EQUATIONS OF STATE
IDEAL FLOW
NONLUMINOUS MATTER
PARTICLE TRACKS
PERTURBATION THEORY
SCALAR FIELDS
SOUND WAVES
VELOCITY