Dark Energy Detected with Supervoids and Superclusters

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.

17 pages. For the more technical ApJ Letter, see 0805.3695. Also see http://ifa.hawaii.edu/cosmowave/supervoids/

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Cited by in corpus (8)

• Challenges for $\Lambda$CDM: An update
• An Imprint of Super-Structures on the Microwave Background due to the Integrated Sachs-Wolfe Effect
• Planck 2015 results. XXI. The integrated Sachs-Wolfe effect
• The integrated Sachs-Wolfe imprints of cosmic superstructures: a problem for ΛCDM
• The stacked ISW signal of rare superstructures in ΛCDM
• Cosmological cross-correlations and nearest neighbor distributions
• Do the observational data favor a local void?
• Cross-correlating Planck with VST ATLAS LRGs: a new test for the ISW effect in the Southern Hemisphere