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 0.5 × 0.5 deg 2 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 3D 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 4.7σ level given reasonable priors, and measure the rate of evolution for 0 < z < 1. We also fit correlation functions to our 3D data as a function of cosmological parameters σ 8 and ΩΛ- We find joint constraints on ΩΛ and σ 8, demonstrating an improvement in accuracy by ≃40 per cent over that available from 2D weak lensing for the same area.
- Cosmological parameters
- Dark matter
- Gravitational lensing
- Large-scale structure of Universe