Constraining gravity at large scales with the 2MASS Photometric Redshift catalogue and Planck lensing

TL;DR

This paper measures the growth of cosmic structure at low redshift by correlating Planck CMB lensing with 2MASS galaxy data, confirming consistency with the standard cosmological model and forecasting improved future constraints.

Contribution

It introduces a new measurement of structure growth at z~0.08 using CMB lensing and galaxy data, and forecasts the potential of upcoming surveys to refine these measurements.

Findings

Measured the amplitude of structure growth as A_D(z=0.08)=1.00±0.21

Found no evidence for systematic effects in the analysis

Forecasted sub-percent constraints on growth history with future surveys

Abstract

We present a new measurement of structure growth at $z \simeq 0.08$ obtained by correlating the cosmic microwave background (CMB) lensing potential map from the \textit{Planck} satellite with the angular distribution of the 2MASS Photometric Redshift galaxies. After testing for, and finding no evidence for systematic effects, we calculate the angular auto- and cross-power spectra. We combine these spectra to estimate the amplitude of structure growth using the bias-independent $D_G$ estimator introduced by Giannantonio et al. 2016. We find that the relative amplitude of $D_G$ with respect to the predictions based on \textit{Planck} cosmology is $A_D(z=0.08) = 1.00 \pm 0.21$, fully consistent with the expectations for the standard cosmological model. Considering statistical errors only, we forecast that a joint analysis between an LSST-like photometric galaxy sample and lensing maps from upcoming ground-based CMB surveys like the Simons Observatory and CMB-S4 can yield sub-percent constraints on the growth history and differentiate between different models of cosmic acceleration.