Cosmology with the Galaxy Bispectrum Multipoles: Optimal Estimation and Application to BOSS Data

Understand

We present a framework for self-consistent cosmological analyses of the full-shape anisotropic bispectrum, including the quadrupole $(\ell=2)$ and hexadecapole $(\ell=4)$ moments.

• This features a novel window-free algorithm for extracting the latter quantities from data, derived using a maximum-likelihood prescription.
• Furthermore, we introduce a theoretical model for the bispectrum multipoles (which does not introduce new free parameters), and test both aspects of the pipeline on several high-fidelity mocks, including the PT Challenge suite of gigantic cumulative volume.
• This establishes that the systematic error is significantly below the statistical threshold, both for the measurement and modeling.