Large-k Limit of Multi-Point Propagators in the RG Formalism

TL;DR

This paper extends the concept of multi-point propagators within the renormalization group formalism to large wave numbers, enhancing the modeling of structure formation and initial non-Gaussianities in cosmology.

Contribution

It introduces a new class of multi-point propagators in the RG framework and derives their large-k behavior, improving theoretical predictions for cosmological power spectra.

Findings

Large-k propagator results match previous Gaussian and non-Gaussian cases.

The new propagators can improve power spectrum and bispectrum calculations.

Enhanced modeling of initial non-Gaussianities in structure formation.

Abstract

Renormalized versions of cosmological perturbation theory have been very successful in recent years in describing the evolution of structure formation in the weakly non-linear regime. The concept of multi-point propagators has been introduced as a tool to quantify the relation between the initial matter distribution and the final one and to push the validity of the approaches to smaller scales. We generalize the n-point propagators that have been considered until now to include a new class of multi-point propagators that are relevant in the framework of the renormalization group formalism. The large-k results obtained for this general class of multi-point propagators match the results obtained earlier both in the case of Gaussian and non-Gaussian initial conditions. We discuss how the large-k results can be used to improve on the accuracy of the calculations of the power spectrum and bispectrum in the presence of initial non-Gaussianities.