Field-theoretic approach to large-scale structure formation

TL;DR

This paper introduces a field-theoretic framework for modeling large-scale structure formation in the universe, connecting quantum field methods with classical particle descriptions and identifying regimes where linear theory breaks down.

Contribution

It develops a novel field-theoretic approach to large-scale structure formation, including a non-local action and a 2PI effective action, bridging quantum and classical descriptions.

Findings

Contrasts phase-space density dynamics with Vlasov equation.

Identifies scales where linear perturbation theory deviates.

Provides a new formalism for large-scale structure modeling.

Abstract

We develop a field-theoretic description of large-scale structure formation by taking the non-relativistic limit of a canonically transformed, real scalar field which is minimally coupled to scalar gravitational perturbations in longitudinal gauge. We integrate out the gravitational constraint fields and arrive at a non-local action which is only specified in terms of the dynamical degrees of freedom. In order to make this framework closer to the classical particle description, we construct the corresponding 2PI effective action truncated at two loop order for a non-squeezed state without field expectation values. We contrast the dynamical description of the coincident time phase-space density to the standard Vlasov description of cold dark matter particles and identify momentum and time scales at which linear perturbation theory will deviate from the standard evolution.