Dark Energy Constraints from Needlets Analysis of Wmap3 and NVSS Data

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dc.creatorPietrobon, Davide
dc.creatorBalbi, Amedeo
dc.creatorMarinucci, Domenico
dc.date2006-11-27
dc.date.accessioned2026-07-07T07:30:57Z
dc.date.available2026-07-07T07:30:57Z
dc.descriptionWe cross-correlate the new 3 year Wilkinson Microwave Anistropy Probe (WMAP3) cosmic microwave background (CMB) data with the NRAO VLA Sky Survey (NVSS) 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 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 cross-correlation with the theoretical predictions of standard, flat cosmological models with a generalized dark energy component parameterized by its density, $\omde$, equation of state $w$ and speed of sound $\cs2$, we find $0.3\leq\omde\leq0.8$ at 95% c.l., independently of $\cs2$ and $w$. If dark energy is assumed to be a cosmological constant ($w=-1$), the bound on density shrinks to $0.41\leq\omde\leq 0.79$. Models without dark energy are excluded at more than $4σ$. The bounds on $w$ depend rather strongly on the assumed value of $\cs2$.
dc.description11th Marcel Grossmann Proceeding
dc.identifierhttps://arxiv.org/abs/astro-ph/0611797
dc.identifierhttp://arxiv.org/abs/astro-ph/0611797
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/118585
dc.subjectAstrophysics
dc.titleDark Energy Constraints from Needlets Analysis of Wmap3 and NVSS Data
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