B14 - Large-scale structure and Dark Energy

Principal Investigators: R. Bender, C. Porciani, A. G. Sánchez


Dark Energy and modified gravity are two possibilities to explain the observed acceleration of the expansion of the Universe. Precise measurements of the large-scale structure of the Universe (as traced by galaxies) can be used to constrain cosmological parameters, in particular those describing the dark-energy equation-of-state, w. At the same time, measurements of the growth factor of density perturbations from redshift-space distortions (which modify the signal of the real-space clustering) can be used to disentangle dark-energy and modified-gravity models. With the advent of extremely large redshift surveys like HETDEX, SDSS III and SDSS IV (eBOSS) we will measure 2-point statistics like the power spectrum (or its Fourier transform, the correlation function) and isolate the features due to baryon acoustic oscillations. We will use several methods to quantify structure at different redshifts, and hence be able to measure not only w, but also its possible time-dependence. However, this requires a thorough and accurate treatment of systematic effects due to both data acquisition and modelling. Bringing together expertise from theorists and observers, and applying novel techniques to the modelling of the clustering statistics, we will be able to infer tight cosmological constraints that will provide a major step towards understanding the physics behind cosmic acceleration.