The impact of the Universe's expansion rate on constraints on modified growth of structure
ArXiv 2207.09896 (2022)
The star formation history in the last 10 billion years from CIB cross-correlations
(2022)
Model-independent constraints on $Ω_m$ and $H(z)$ from the link between geometry and growth
ArXiv 2201.07025 (2022)
The growth of density perturbations in the last ∼10 billion years from tomographic large-scale structure data
Journal of Cosmology and Astroparticle Physics IOP Publishing 10:2021 (2021) 030
Abstract:
In order to investigate the origin of the ongoing tension between the amplitude of matter fluctuations measured by weak lensing experiments at low redshifts and the value inferred from the cosmic microwave background anisotropies, we reconstruct the evolution of this amplitude from z ∼ 2 using existing large-scale structure data. To do so, we decouple the linear growth of density inhomogeneities from the background expansion, and constrain its redshift dependence making use of a combination of 6 different data sets, including cosmic shear, galaxy clustering and CMB lensing. We analyze these data under a consistent harmonic-space angular power spectrum-based pipeline. We show that current data constrain the amplitude of fluctuations mostly in the range 0.2 < z < 0.7, where it is lower than predicted by Planck. This difference is mostly driven by current cosmic shear data, although the growth histories reconstructed from different data combinations are consistent with each other, and we find no evidence of systematic deviations in any particular experiment. In spite of the tension with Planck, the data are well-described by the ΛCDM model, albeit with a lower value of S8 ≡ σ8(Ωm/0.3)0.5 . As part of our analysis, we find constraints on this parameter of S8 = 0.7781 ± 0.0094 (68% confidence level), reaching almost percent-level errors comparable with CMB measurements, and 3.4σ away from the value found by Planck.The growth of density perturbations in the last $\sim$10 billion years from tomographic large-scale structure data
ArXiv 2105.12108 (2021)