Constraining primordial and gravitational mode coupling with the position-dependent bispectrum of the large-scale structure

Abstract

We develop and study the position-dependent bispectrum. It is a generalization of the recently proposed position-dependent power spectrum method of measuring the squeezed-limit bispectrum. The position-dependent bispectrum can similarly be used to measure the squeezed-limit trispectrum in which one of the wavelengths is much longer than the other three. In this work, we will mainly consider the case in which the three smaller wavelengths are nearly the same (the equilateral configuration). We use the Fisher information matrix to forecast constraints on bias parameters and the amplitude of primordial trispectra from the position-dependent bispectrum method. We find that the method can constrain the local-type $g_{\mathrm{NL}}$ at a level of $\sigma (g_{\mathrm{NL}}^{\mathrm{local}})\approx 3\times 10^5$ for a large volume SPHEREx-like survey; improvements can be expected by including all the triangular configurations of the bispectra rather than just the equilateral configuration. However, the same measurement would also constrain a much larger family of trispectra than local $g_{\mathrm{NL}}$ model. We discuss the implications of the forecasted reach of future surveys in terms of super cosmic variance uncertainties from primordial non-Gaussianities.

arXiv comment5 figures, 2 tables; v2: small changes to match the PRD version

References in corpus (24)

• Planck 2015 results. XIII. Cosmological parameters
• Efficient Computation of CMB anisotropies in closed FRW models
• Large-Scale Structure of the Universe and Cosmological Perturbation Theory
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Planck 2015 results. XVII. Constraints on primordial non-Gaussianity
• The power spectrum and bispectrum of SDSS DR11 BOSS galaxies I: bias and gravity
• Probing Primordial Non-Gaussianity with Large-Scale Structure
• Constraints on primordial non-Gaussianity from 800,000 photometric quasars
• Primordial non-Gaussianity in the Bispectrum of the Halo Density Field
• Position-dependent power spectrum of the large-scale structure: a novel method to measure the squeezed-limit bispectrum
• The extended Baryon Oscillation Spectroscopic Survey (eBOSS): a cosmological forecast
• A Note on the Consistency Condition of Primordial Fluctuations
• Galaxy Bias and Halo-Occupation Numbers from Large-Scale Clustering
• The power spectrum and bispectrum of SDSS DR11 BOSS galaxies II: cosmological interpretation
• The angle-averaged squeezed limit of nonlinear matter N-point functions
• Halo clustering and g_{NL}-type primordial non-Gaussianity
• Angular averaged consistency relations of large-scale structures
• Statistical Naturalness and non-Gaussianity in a Finite Universe
• Large-scale anomalies in the cosmic microwave background as signatures of non-Gaussianity
• Equal-time Consistency Relations in the Large-Scale Structure of the Universe
• Primordial non-Gaussianity in the bispectra of large-scale structure
• Non-Gaussian Mode Coupling and the Statistical Cosmological Principle
• Cosmic Variance of the Spectral Index from Mode Coupling
• Non-local bispectra from super cosmic variance

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• The Hunt for Primordial Interactions in the Large Scale Structures of the Universe
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• Self-calibration of weak lensing systematic effects using combined two- and three-point statistics
• The squeezed matter bispectrum covariance with responses
• Density reconstruction from biased tracers and its application to primordial non-Gaussianity
• The halo squeezed-limit bispectrum with primordial non-Gaussianity: a power spectrum response approach
• Reconstructing the Long-wavelength Matter Density Fluctuation Modes from the Scalar-Type Clustering Fossils