Bispectrum as Baryon Acoustic Oscillation Interferometer

TL;DR

This paper introduces a novel interference-based method to efficiently identify bispectrum triangles that enhance baryon acoustic oscillation signals, improving BAO constraints and reducing computational costs in galaxy survey analyses.

Contribution

It presents a new approach leveraging interference in the bispectrum to select BAO-amplifying triangles, significantly improving analysis efficiency and constraints.

Findings

Reduces covariance estimation costs

Enhances BAO constraints by 30% equivalent

Simplifies integration of bispectrum data in surveys

Abstract

The galaxy bispectrum, measuring excess clustering of galaxy triplets, offers a probe of dark energy via baryon acoustic oscillations (BAOs). However up to now it has been severely underused due to the combinatorically explosive number of triangles. Here we exploit interference in the bispectrum to identify triangles that amplify BAOs. This approach reduces the computational cost of estimating covariance matrices, offers an improvement in BAO constraints equivalent to lengthening BOSS by 30%, and simplifies adding bispectrum BAO information to future large-scale redshift survey analyses.