Crosscorrelation of Planck CMB lensing with DESIlike LRGs
Abstract
Crosscorrelations between the lensing of the cosmic microwave background (CMB) and other tracers of largescale structure provide a unique way to reconstruct the growth of dark matter, break degeneracies between cosmology and galaxy physics, and test theories of modified gravity. We detect a crosscorrelation between Dark Energy Spectroscopic Instrument (DESI)like luminous red galaxies (LRGs) selected from DECam Legacy Survey imaging and CMB lensing maps reconstructed with the Planck satellite at a significance of S/N = 27.2 over scales ℓ_{min} = 30, ℓ_{max} = 1000. To correct for magnification bias, we determine the slope of the LRG cumulative magnitude function at the faint limit as s = 0.999 ± 0.015, and find corresponding corrections of the order of a few per cent for $C^{\kappa g}_{\ell }, C^{gg}_{\ell }$ across the scales of interest. We fit the largescale galaxy bias at the effective redshift of the crosscorrelation z_{eff} ≍ 0.68 using two different bias evolution agnostic models: a HaloFit times linear bias model where the bias evolution is folded into the clusteringbased estimation of the redshift kernel, and a Lagrangian perturbation theory model of the clustering evaluated at z_{eff}. We also determine the error on the bias from uncertainty in the redshift distribution; within this error, the two methods show excellent agreement with each other and with DESI survey expectations.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 March 2021
 DOI:
 10.1093/mnras/staa3927
 arXiv:
 arXiv:2010.04698
 Bibcode:
 2021MNRAS.501.6181K
 Keywords:

 cosmic background radiation;
 largescale structure of Universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 18 pages, 14 figures, 6 tables