[ExI] dark energy and CMB variations

[Damien Broderick]

http://arxiv.org/abs/0805.2974


Dark Energy Detected with Supervoids and Superclusters

Authors: 
<http://arxiv.org/find/astro-ph/1/au:+Granett_B/0/1/0/all/0/1>Benjamin 
R. Granett, 
<http://arxiv.org/find/astro-ph/1/au:+Neyrinck_M/0/1/0/all/0/1>Mark 
C. Neyrinck, 
<http://arxiv.org/find/astro-ph/1/au:+Szapudi_I/0/1/0/all/0/1>István 
Szapudi (IfA, Hawaii)
(Submitted on 20 May 2008 
(<http://arxiv.org/abs/0805.2974v1>v1), last 
revised 10 Jul 2008 (this version, v2))
Abstract: The observed apparent acceleration of 
the universe is usually attributed to negative 
pressure from a mysterious dark energy. This 
acceleration causes the gravitational potential 
to decay, heating or cooling photons travelling 
through crests or troughs of large-scale matter 
density fluctuations. This phenomenon, the 
late-time integrated Sachs-Wolfe (ISW) effect, 
has been detected, albeit at low significance, by 
cross-correlating various galaxy surveys with the 
Cosmic Microwave Background (CMB). Recently, the 
best evidence has come from the statistical 
combination of results from multiple correlated 
galaxy data sets. Here we show that vast 
structures identified in a galaxy survey project 
an image onto the CMB; stacking regions aligned 
with superclusters produces a hot spot, and 
supervoids, a cold spot. At over 4 sigma, this is 
the clearest evidence of the ISW effect to date. 
For the first time, our findings pin the effect 
to discrete structures. The ISW signal from 
supervoids and superclusters can be combined with 
other cosmological probes to constrain dark 
energy and cosmological parameters. In addition, 
our findings make it more plausible that the 
extreme Cold Spot and other anomalies in the CMB are caused by supervoids.

Comments: 17 pages. For the more technical ApJ 
Letter, see 
<http://arxiv.org/abs/0805.3695>0805.3695. Also 
see <http://ifa.hawaii.edu/cosmowave/supervoids/>this http URL
Subjects: Astrophysics (astro-ph)
Cite as: <http://arxiv.org/abs/0805.2974v2>arXiv:0805.2974v2 [astro-ph]


Submission history

From: Mark C. Neyrinck 
[<http://arXiv.org/auth/show-email/74b4d1d3/0805.2974>view email]
<http://arxiv.org/abs/0805.2974v1>[v1] Tue, 20 May 2008 01:46:10 GMT (957kb)
[v2] Thu, 10 Jul 2008 03:59:19 GMT (669kb)