The strangest feature of our current cosmological model is the observation that the expansion rate of the universe is accelerating. Our ignorance is summarized by the simple name for the cause of the observed phenomenon: dark energy. Alternatively, it could be explained by the break down of Einstein's gravitation theory on cosmological scales. Observations of large-scale structure have played an important role in developing our standard cosmological model and will play an essential role in our investigations of the origin of cosmic acceleration.
I will illustrate how it is possible to test different models of gravity and dark energy via galaxy clustering using forthcoming cosmological galaxy surveys.
However, the theoretical models currently used to interpret the data often rely on simplifications that make them not accurate enough for precise measurements at very large scales.
I will show improvements to the theoretical modeling that arise when using a proper general relativistic formalism, in particular focusing on relativistic terms in radial correlations. In wide and deep surveys those corrections will need to be taken into account if we want to measure the growth rate parameter with high precision without introducing systematic errors.
