Analysis of BOSS Galaxy Data with Weighted Skew-Spectra

TL;DR

This paper introduces the use of weighted skew-spectra to analyze non-Gaussian features in galaxy survey data, specifically targeting primordial non-Gaussianity shapes, and applies it to SDSS-BOSS data with consistent results.

Contribution

The study is the first to apply weighted skew-spectra to galaxy survey data for non-Gaussian analysis, incorporating EFT models and survey systematics.

Findings

Consistent $f_{NL}^{equil}$ constraints with previous studies.

Systematic effects impact the estimation of $f_{NL}^{ortho}$.

Validated analysis pipeline with Nseries simulations.

Abstract

We present the first application of the weighted skew-spectra to analyze non-Gaussian information in galaxy survey data. Using the tree-level galaxy skew-spectra together with the one-loop power spectrum multipoles, we analyze the Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) galaxy clustering data, and target our search towards the equilateral bispectrum shape of primordial non-Gaussianity. We use the Effective Field Theory model for the galaxy power spectrum and bispectrum, and account for systematic effects, such as the survey geometry. From our likelihood analysis, we find $f_{\rm NL}^{\rm equil}=-34^{+296}_{-334}$ at $68\%$ CL, consistent with previous works, while systematic errors from our treatment of the survey geometry lead to an unreliable estimation of $f_{\rm NL}^{\rm ortho}$. We further constrain the bias and counterterm parameters, while keeping the cosmology fixed to $\textit{Planck }2018$ values. As a check, we also validate our analysis pipeline using the ${\tt Nseries}$ simulation suite.