Field Theoretic Approaches to Large Scale Structure

Abstract

We explore the use of a variety of field theoretical methods in LSS. We first probe the linear and mildly non-linear regimes using Schwinger Keldysh formalism. Here we are able to include EFT corrections due to pressure, viscosity and noise at the level of the propagator, and also get analytical results for more general initial conditions deviating from the usual power law \(P \propto k^{n}\). To study the strongly non-linear regime, we use a variety of CFT-inspired methods. Tools such as symmetry constraints, gravity duals and conformal perturbation theory exploit the Lifschitz symmetry to expose different aspects of large scale structure. Symmetry based methods have been successfully applied to other Lifschitz systems. At the moment we are able to obtain few concrete results in the strongly non-linear regime, although there are many promising hints that we are in the right direction, such as the fact that conformal perturbation theory reproduces the known consistency relations and correlation functions for LSS. With a better understanding in particular of the CFTs that are deformed or reduced to get LSS, the tools presented could be used to capture the strongly non-linear dynamics of LSS.