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

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 $A_{rm ISW}=Delta T^{rm data} / Delta T^{rm theory}=1$, 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_{rm ISW}approx4.1pm2.0$ amplitude. The combination with independent BOSS data reveals an ISW imprint of supervoids at the $3.3sigma$ significance level with an enhanced $A_{rm ISW}approx5.2pm1.6$ amplitude. The tension with $Lambda$CDM predictions is equivalent to $2.6sigma$ and remains unexplained.