Wide-area tomography of CMB lensing and the growth of cosmological density fluctuations

Understand

We describe a tomographic dissection of the Planck CMB lensing data, cross-correlating this map with galaxies in different ranges of photometric redshift.

• We use the nearly all-sky 2MPZ and WISExSCOS catalogues for z<0.35, extending to z<0.6 using SDSS.
• We describe checks for consistency between the different datasets, and perform a test for possible leakage of thermal Sunyaev--Zel'dovich signal into our cross-correlation measurements.
• The amplitude of the cross-correlation allows us to estimate the evolution of density fluctuations as a function of redshift, thus providing a test of theories of modified gravity.