Evolution of the Dark Matter Distribution with 3-D Weak Lensing

Abstract

We present a direct detection of the growth of large-scale structure, using weak gravitational lensing and photometric redshift data from the COMBO-17 survey. We use deep R-band imaging of two 0.25 square degree fields, affording shear estimates for over 52000 galaxies; we combine these with photometric redshift estimates from our 17 band survey, in order to obtain a 3-D shear field. We find theoretical models for evolving matter power spectra and correlation functions, and fit the corresponding shear correlation functions to the data as a function of redshift. We detect the evolution of the power at the 7.7 sigma level given minimal priors, and measure the rate of evolution for 0<z<1. We also fit correlation functions to our 3-D data as a function of cosmological parameters sigma_8 and Omega_Lambda. We find joint constraints on Omega_Lambda and sigma_8, demonstrating an improvement in accuracy by a factor of 2 over that available from 2D weak lensing for the same area.