# Time-sliced perturbation theory with primordial non-Gaussianity and effects of large bulk flows on inflationary oscillating features

## TL;DR

This paper extends time-sliced perturbation theory to include primordial non-Gaussianity, revealing how large bulk flows damp primordial oscillating features through systematic IR resummation.

## Contribution

It introduces a new formulation of TSPT that incorporates non-Gaussian initial conditions and clarifies the IR structure of non-Gaussian vertices.

## Key findings

- New TSPT formulation with non-Gaussian initial conditions
- Damping of primordial oscillations due to large bulk flows
- Derivation of damping factors via IR resummation

## Abstract

We extend the formalism of time-sliced perturbation theory (TSPT) for cosmological large-scale structure to include non-Gaussian initial conditions. We show that in such a case the TSPT interaction vertices acquire new contributions whose time-dependence factorizes for the Einstein-de Sitter cosmology. The new formulation is free from spurious infrared (IR) enhancements and reveals a clear IR structure of non-Gaussian vertices. We use the new technique to study the evolution of oscillating features in primordial statistics and show that they are damped due to non-linear effects of large bulk flows. We derive the damping factors for the oscillating primordial power spectrum and bispectrum by means of a systematic IR resummation of relevant Feynman diagrams.