Squeezing fNL out of the matter bispectrum with consistency relations

• DOI: 10.1103/physrevd.106.123525
• Publication Date: 2022-12-29T15:02:21Z
• Authors: Samuel Goldstein; Angelo Esposito; Oliver H. E. Philcox; Lam Hui; J. Colin Hill; Roman Scoccimarro; Maximilian H. Abi...
• Keywords: High Energy Physics - Theory; Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th); FOS: Physical sciences; Primordial non-gaussianity, consistency relations, large scale structures; General Relativity and Quantum Cosmology (gr-qc); General Relativity and Quantum Cosmology; Astrophysics - Cosmology and Nongalactic Astrophysics

We show how consistency relations can be used to robustly extract the amplitude of local primordial non-Gaussianity (${f}_{\mathrm{NL}}$) from squeezed limit matter bispectrum, well into nonlinear regime. First, we derive a nonperturbative relation between and leading term in revising some results present literature. This is then successfully measure ${f}_{\mathrm{NL}}$ $N$-body simulations. discuss dependence our on different scale cuts redshifts. Specifically, analysis strongly dependent choice smallest soft momentum, ${q}_{\mathrm{min}}$, which most sensitive bispectrum contributions, but largely independent largest hard ${k}_{\mathrm{max}}$, due non-Gaussian nature covariance. also constraints improve at higher redshift, reduced off-diagonal In particular, for simulation with ${f}_{\mathrm{NL}}=100$ volume $(2.4\text{ }\text{ }\mathrm{Gpc}/h{)}^{3}$, ${f}_{\mathrm{NL}}=98\ifmmode\pm\else\textpm\fi{}12$ redshift $z=0$ ${f}_{\mathrm{NL}}=97\ifmmode\pm\else\textpm\fi{}8$ $z=0.97$. Finally, compare Fisher forecast, showing that current version satisfactorily close error. regard this as first step towards realistic application constrain using observations.