Constraining Gravity at Large Scales with the 2MASS Photometric Redshift Catalog and Planck Lensing

We present a new measurement of structure growth at z ≃ 0.08 obtained by correlating the cosmic microwave background (CMB) lensing potential map from the 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 DG estimator introduced by Giannantonio et al. We find that the relative amplitude of DG with respect to the predictions based on Planck cosmology is AD (z = 0.08) = 1.00 ± 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