Bispectrum as Baryon Acoustic Oscillation Interferometer

Understand

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.