Starts 12 Feb 2019 14:30
Ends 12 Feb 2019 16:00
Central European Time
ICTP
Leonardo Building - Luigi Stasi Seminar Room
Abstract. We discuss relativistic corrections to large scale structure observables. These are expected to yield contributions comparable to fNL of a few, and therefore potentially observable in future surveys. We then focus on the large scale structure bispectrum in the squeezed limit, which couples large with small scales. Since relativity is important at large scales and non-linear loop corrections are important at small scales, the proper calculation of the observed bispectrum in this limit requires a non-linear relativistic calculation. We compute the matter bispectrum in general relativity in the weak field approximation. The calculation is as involved as existing second-order results. For the bispectrum, we find relativistic corrections to be as large as the newtonian result in the squeezed limit. In that limit relativistic one-loop contributions, which we compute for the first time, can be as large as tree level results and have the sa dependence as a primordial local non-Gaussianity signal where k is the momentum approaching zero. Moreover, we find the time dependence of the relavistic corrections to the bispectrum to be the same as that of a primordial non-Gaussianity signal.