The CMB has done a wonderful job in constraining cosmological parameters, and so improving our understanding of the Universe on large scales. Advancing beyond this will require significant improvements in harnessing the information content of large scale structure surveys. This will necessitate greater theoretical modelling to improve the range of scales that can be analysed, allied to improved measurement techniques of higher order statistics. Through the prism of two projects I’m currently completing with members of the group here at Sussex, I will describe progress in both these directions.
First off, I will try and lead you all through the minefield of a framework known as the Effective Field Theory of Large Scale Structure. Hopefully you’ll be convinced that it’s really not so conceptually difficult, and is a useful tool! Having described how the calculation works for dark matter, I’ll sketch how everything follows through for redshift space distortions. Following this, I’ll discuss work on alternative estimators for the three-point function of large scale structure. The goal here is to find a compressed statistic which alleviates the extremely computationally challenging requirements for the covariance matrix, while retaining most of the information. Development of complementary estimators will also be key in future surveys for robustness tests of this statistic, which is vital to break degeneracies between various cosmological parameters.