Tomotsugu Goto, Istvan Szapudi, Benjamin R. Granett
We estimated the cross-power spectra of a galaxy sample from the Wide-field
Infrared Survey Explorer (WISE) survey with the 7-year Wilkinson Microwave
Anisotropy Probe (WMAP) temperature anisotropy maps. A conservatively-selected
galaxy sample covers ~13000sq.deg, with a median redshift of z=0.15.
Cross-power spectra show correlations between the two data sets with no
discernible dependence on the WMAP Q, V and W frequency bands. We interpret
these results in terms of the the Integrated Sachs-Wolfe (ISW) effect: for the
|b|>20 deg sample at l=6-87, we measure the amplitude (normalized to be 1 for
vanilla LambdaCDM expectation) of the signal to be 3.4+-1.1, i.e., 3.1 sigma
detection. We discuss other possibilities, but at face value, the detection of
the linear ISW effect in a flat universe is caused by large scale decaying
potentials, a sign of accelerated expansion driven by Dark Energy.
View original:
http://arxiv.org/abs/1202.5306
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