More out of less: an excess integrated Sachs-Wolfe signal from supervoids mapped out by the Dark Energy Survey

Abstract

The largest structures in the cosmic web probe the dynamical nature of dark energy through their integrated Sachs-Wolfe imprints. In the strength of the signal, typical cosmic voids have shown good consistency with expectation A(ISW) = Delta T-data/Delta T-theory = 1, given the substantial cosmic variance. Discordantly, large-scale hills in the gravitational potential, or supervoids, have shown excess signals. In this study, we mapped out 87 new supervoids in the total 5000 deg(2) footprint of the Dark Energy Survey at 0.2 < z < 0.9 to probe these anomalous claims. We found an excess imprinted profile with A(ISW) approximate to 4.1 +/- 2.0 amplitude. The combination with independent BOSS data reveals an ISW imprint of supervoids at the 3.3 sigma significance level with an enhanced A(ISW) approximate to 5.2 +/- 1.6 amplitude. The tension with Lambda CDM predictions is equivalent to 2.6 sigma and remains unexplained.