Princeton University/Institute for Advanced Study Early Universe/Cosmology Lunch Discussion

Organizers are David Spergel, Princeton University, and Matias Zaldarriaga, Institute for Advanced Study. The lunch will be held at either Princeton University or the Institute for Advanced Study. Check the calendar for the meeting location. This week's meeting is at Princeton University. Attendees can bring lunch. ABSTRACT: One of the challenges of modern cosmology is to discriminate among the many models of inflation which are able to predict a scale invariant spectrum as observed in the Cosmic Microwave Backround. One of the features which could help in this effort is non-Gaussianity, namely if the random seeds of the initial perturbations are to be described with higher than 2-point statistics. Non-Gaussianity in its simplest form is generally parametrized by a non-linearity parameter, fNL. With the advent of large scale galaxy surveys, constraints on primordial non-Gaussianity are expected to reach order O(fNL) ~1. In order to fully exploit the potential of these future surveys, a deep theoretical understanding of the signatures imprinted by primordial non-Gaussianity on the large scale structure of the Universe is necessary. In this talk we will introduce the peak approach to halo clustering, which provides a framework to predict such signatures. We will show in detail how this prediction is calculated and compare it to other methods (such as the peak-background split ansatz). Lastly, we will compare these different predictions to direct measurements of primordial non-Gaussianity in N body simulations and discuss the result.