Cosmological constraints from a combination of galaxy clustering and lensing – III. Application to SDSS data

Abstract

We simultaneously constrain cosmology and galaxy bias using measurements of galaxy abundances, galaxy clustering and galaxy-galaxy lensing taken from the Sloan Digital Sky Survey. We use the conditional luminosity function (which describes the halo occupation statistics as a function of galaxy luminosity) combined with the halo model (which describes the non-linear matter field in terms of its halo building blocks) to describe the galaxy-dark matter connection. We explicitly account for residual redshift-space distortions in the projected galaxy-galaxy correlation functions, and marginalize over uncertainties in the scale dependence of the halo bias and the detailed structure of dark matter haloes. Under the assumption of a spatially flat, vanilla cold dark matter ( CDM) cosmology, we focus on constraining the matter density, m , and the normalization of the matter power spectrum, 8 , and we adopt 7-year Wilkinson Microwave Anisotropy Probe (WMAP7) priors for the spectral index, n, the Hubble parameter, h, and the baryon density, b . We obtain that m = 0.278 +0.023 -0.026 and 8 = 0.763 +0.064 -0.049