Wide-area tomography of CMB lensing and the growth of cosmological density fluctuations. Issue 1 (23rd August 2018)

• Record Type: Journal Article
• Authors: Peacock, J A; Bilicki, M
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 481:Issue 1(2018)
• Page Start: 1133
• Page End: 1148
• Publication Date: 2018-08-23
• Subjects: large-scale structure of Universe -- cosmic background radiation; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty2314
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: 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 WISE×SCOS catalogues for $z$ < 0.35, extending to $z$ < 0.6 using SDSS. We describe checks for consistency between the different data sets, 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. Assuming the common parametrization for the logarithmic growth rate, f g = Ωm ($z$ ) γ, we infer γ = 0.77 ± 0.18 when Ωm is fixed using external data. Thus CMB lensing tomography is currently consistent with Einstein gravity, where γ = 0.55 is expected. We discuss how such constraints may be expected to improve with future data.