Non-linear damping of superimposed primordial oscillations on the matter power spectrum in galaxy surveys

TL;DR

This paper investigates how non-linear gravitational clustering affects primordial oscillations in the matter power spectrum, providing a fitting formula to improve constraints from galaxy surveys like Euclid and Subaru.

Contribution

It introduces a Gaussian envelope model for non-linear damping of primordial oscillations in the matter power spectrum based on high-resolution N-body simulations.

Findings

Gaussian damping envelope fits simulation data with sub-percent accuracy

Forecasts Euclid and Subaru's ability to detect primordial oscillations on non-linear scales

Demonstrates combined galaxy survey and CMB analysis enhances primordial feature constraints

Abstract

Galaxy surveys are an important probe for superimposed oscillations on the primordial power spectrum of curvature perturbations, which are predicted in several theoretical models of inflation and its alternatives. In order to exploit the full cosmological information in galaxy surveys it is necessary to study the matter power spectrum to fully non-linear scales. We therefore study the non-linear clustering in models with superimposed linear and logarithmic oscillations to the primordial power spectrum by running high-resolution dark-matter-only N-body simulations. We fit a Gaussian envelope for the non-linear damping of superimposed oscillations in the matter power spectrum to the results of the N-body simulations for $k \lesssim 0.6\ h/$Mpc at $0 \leq z \leq 5$ with an accuracy below the percent. We finally use this fitting formula to forecast the capabilities of future galaxy surveys, such as Euclid and Subaru, to probe primordial oscillation down to non-linear scales alone and in combination with the information contained in CMB anisotropies.