Dark Energy Survey Year 3 results: Imprints of cosmic voids and superclusters in the Planck CMB lensing map

Abstract

The CMB lensing signal from cosmic voids and superclusters probes the growth of structure in the low-redshift cosmic web. In this analysis, we cross-correlated the Planck CMB lensing map with voids detected in the Dark Energy Survey Year 3 (Y3) data set (∼5,000 deg2), expanding on previous measurements that used Y1 catalogues (∼1,300 deg2). Given the increased statistical power compared to Y1 data, we report a 6.6σ detection of negative CMB convergence (κ) imprints using approximately 3,600 voids detected from a redMaGiC luminous red galaxy sample. However, the measured signal is lower than expected from the MICE N-body simulation that is based on the ΛCDM model (parameters Ωm = 0.25, σ8 = 0.8), and the discrepancy is associated mostly with the void centre region. Considering the full void lensing profile, we fit an amplitude Aκ = κDES4pt/κMICE4pt to a simulation-based template with fixed shape and found a moderate 2σ deviation in the signal with Aκ ≈ 0.79 ± 0.12. We also examined the WebSky simulation that is based on a Planck 2018 ΛCDM cosmology, but the results were even less consistent given the slightly higher matter density fluctuations than in MICE. We then identified superclusters in the DES and the MICE catalogues, and detected their imprints at the 8.4σ level; again with a lower-than-expected Aκ = 0.84 ± 0.10 amplitude. The combination of voids and superclusters yields a 10.3σ detection with an Aκ = 0.82 ± 0.08 constraint on the CMB lensing amplitude, thus the overall signal is 2.3σ weaker than expected from MICE.

Is the observable Universe consistent with the cosmological principle?

“…Throughout, it is worth bearing in mind that a number of discrepancies or tensions have arisen between Planck inferences of cosmological parameters based on the CMB [48] and determinations of the same quantities in the late Universe. These ΛCDM tensions, which primarily involve H 0 [47,[53][54][55][56][57][58][59][60], S 8 [192][193][194][195], and to a lesser extent curvature [123,315], and more recently A ISW [316,317], are often framed as early versus late Universe tensions [318], see [50] for a recent review 44 . Notably, this ΛCDM tension debate happens essentially within FLRW.…”

“…If the Universe is not FLRW, but we view it through the prism of FLRW, cosmological tensions are inevitable. Interestingly, a host of fascinating observational tensions exist, including the H 0 tension [47,[53][54][55][56][57][58][59][60], the S 8 tension [192][193][194][195], potentially a curvature tension [123,315], and an A ISW tension [316,317]. Finally, even if the best quality data set underpinning modern cosmology, namely the CMB, is considered, and the results of [90,91] are correct-the well documented hemispherical power asymmetry suggests they may well be-then one is looking at ∼10% variations in cosmological parameters, most notably H 0 , despite Planck errors at the ∼1% level.…”

Hubble Tension: The Evidence of New Physics

“…The local void model has been disfavored by the SNe Ia data [517][518][519], but can not completely be ruled out. Of course, there is also some evidence supporting the existence of the local void model [520][521][522]. The reasons for the transition of the Cepheid parameters and the M B transition of SNe Ia are still unclear.…”

Cosmic web & caustic skeleton: non-linear constrained realizations — 2D case studies

“…Cosmological observations are producing ever more detailed maps of the spatial galaxy distribution, while a range of observational data is accessing the neutral and ionized gas distribution in the cosmic web, and even that of the dark matter distribution [13,14]. In the coming years a large array of major observational redshift surveys, in particular, those of Euclid, DESI, the Vera Rubin observatory, and SKA -will map the weblike organization of galaxies over unprecedented large cosmic volumes.…”