Measurements of how matter clusters on large scales can help answer some of the remaining mysteries in Cosmology. Even though the large scale dynamics of the matter in our Universe is simple, the theory that describes fluctuations on large scales is modified by the effect of the very non-linear dynamics on smaller scales. The large scale dynamics is described by the Effective Theory of Large Scale Structure framework. I will describe the framework. I will describe its application to current data, in particular a determination of the Hubble constant (H0 = 68.6±1.1 km s−1Mpc−1) which does not use CMB data. A major challenge in this framework is to calibrate the free parameters of the theory that encode the effects of the small scales on the large ones. Constraining these parameters from the large scale clustering data leads to significant degradation in the cosmological constraints. One could imagine constraining these parameters using a combination of small scale simulations and observations. I will discuss the accuracy required of this calibration to improve constraints from future surveys.
The seminar is only on zoom: