Lifting Primordial Non-Gaussianity Above the Noise

TL;DR

This paper demonstrates that modeling matter non-linearities with the Effective Field Theory approach can significantly improve constraints on primordial non-Gaussianity from future large-scale structure surveys, especially for local PNG.

Contribution

The study shows that EFT corrections are essential for enhancing sensitivity to PNG and provides a detailed method to incorporate theoretical errors into forecasts.

Findings

EFT modeling improves bounds on local PNG.

Theoretical errors are crucial for accurate Fisher forecasts.

Current understanding limits detection of equilateral PNG.

Abstract

Primordial non-Gaussianity (PNG) in Large Scale Structures is obfuscated by the many additional sources of non-linearity. Within the Effective Field Theory approach to Standard Perturbation Theory, we show that matter non-linearities in the bispectrum can be modeled sufficiently well to strengthen current bounds with near future surveys, such as Euclid. We find that the EFT corrections are crucial to this improvement in sensitivity. Yet, our understanding of non-linearities is still insufficient to reach important theoretical benchmarks for equilateral PNG, while, for local PNG, our forecast is more optimistic. We consistently account for the theoretical error intrinsic to the perturbative approach and discuss the details of its implementation in Fisher forecasts.