Designing an Inflation Galaxy Survey: how to measure $\sigma (f_{\mathrm{NL}})\sim 1$ using scale-dependent galaxy bias

Abstract

The most promising method for measuring primordial non-Gaussianity in the post-Planck era is to detect large-scale, scale-dependent galaxy bias. Considering the information in the galaxy power spectrum, we here derive the properties of a galaxy clustering survey that would optimize constraints on primordial non-Gaussianity using this technique. Specifically, we ask the question what survey design is needed to reach a precision $\sigma (f_{\mathrm{NL}}^{\mathrm{loc}})\approx 1$. To answer this question, we calculate the sensitivity to $f_{\mathrm{NL}}^{\mathrm{loc}}$ as a function of galaxy number density, redshift accuracy and sky coverage. We include the multitracer technique, which helps minimize cosmic variance noise, by considering the possibility of dividing the galaxy sample into stellar mass bins. We show that the ideal survey for $f_{\mathrm{NL}}^{\mathrm{loc}}$ looks very different than most galaxy redshift surveys scheduled for the near future. Since those are more or less optimized for measuring the BAO scale, they typically require spectroscopic redshifts. On the contrary, to optimize the $f_{\mathrm{NL}}^{\mathrm{loc}}$ measurement, a deep, wide, multi-band imaging survey is preferred. An uncertainty $\sigma (f_{\mathrm{NL}}^{\mathrm{loc}})=1$ can be reached with a full-sky survey that is complete to an $i$-band AB magnitude $i\approx 23$ and has a number density $\sim 8$ arcmin${}^{-2}$. Requirements on the multi-band photometry are set by a modest photo-$z$ accuracy $\sigma (z)/(1+z)<0.1$ and the ability to measure stellar mass with a precision $\sim 0.2$ dex or better (or another proxy for halo mass with equivalent scatter). While here we focus on the information in the power spectrum, even stronger constraints can potentially be obtained with the galaxy bispectrum.

18 pages, 10 figures

References in corpus (11)

• 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
• Measuring primordial non-gaussianity without cosmic variance
• New Perspective on Galaxy Clustering as a Cosmological Probe: General Relativistic Effects
• CMBPol Mission Concept Study: Probing Inflation with CMB Polarization
• Constraints on primordial non-Gaussianity from 800,000 photometric quasars
• On Separate Universes
• Constraining primordial non-Gaussianity via a multitracer technique with surveys by Euclid and Square Kilometre Array
• Using Large Scale Structure to test Multifield Inflation
• Is There Scale-Dependent Bias in Single-Field Inflation?
• Optimal Weighting in Galaxy Surveys: Application to Redshift-Space Distortions

Cited by in corpus (49)

• Exploring Cosmic Origins with CORE: Inflation
• Parameter constraints from cross-correlation of CMB lensing with galaxy clustering
• Redshift-weighted constraints on primordial non-Gaussianity from the clustering of the eBOSS DR14 quasars in Fourier space
• Cosmological Measurements with General Relativistic Galaxy Correlations
• Primordial Non-Gaussianity from Biased Tracers: Likelihood Analysis of Real-Space Power Spectrum and Bispectrum
• Towards a measurement of the spectral runnings
• Can we actually constrain $f_{\mathrm{NL}}$ using the scale-dependent bias effect? An illustration of the impact of galaxy bias uncertainties using the BOSS DR12 galaxy power spectrum
• On the impact of galaxy bias uncertainties on primordial non-Gaussianity constraints
• Galaxy bias and primordial non-Gaussianity: insights from galaxy formation simulations with IllustrisTNG
• Curvature constraints from Large Scale Structure
• Large-scale Maps of the Cosmic Infrared Background from Planck
• Predictions for local PNG bias in the galaxy power spectrum and bispectrum and the consequences for $f_{\mathrm{NL}}$ constraints
• The Hunt for Primordial Interactions in the Large Scale Structures of the Universe
• Primordial non-Gaussianities after Planck 2015: an introductory review
• Bayesian field-level inference of primordial non-Gaussianity using next-generation galaxy surveys
• Dark Energy Survey: A 2.1% measurement of the angular Baryonic Acoustic Oscillation scale at redshift $z_{\mathrm{eff}}$=0.85 from the final dataset
• Imprints of Oscillatory Bispectra on Galaxy Clustering
• Shot noise and biased tracers: a new look at the halo model
• Biasing and the search for primordial non-Gaussianity beyond the local type
• Assembly bias in the local PNG halo bias and its implication for $f_{\mathrm{NL}}$ constraints
• Disantangling the effects of Doppler velocity and primordial non-Gaussianity in galaxy power spectra
• Constraint of Void Bias on Primordial non-Gaussianity
• Optimising primordial non-Gaussianity measurements from galaxy surveys
• Primordial non-Gaussianities and zero bias tracers of the Large Scale Structure
• Learning to Concentrate: Multi-tracer Forecasts on Local Primordial Non-Gaussianity with Machine-Learned Bias
• Non-Gaussianity Constraints using Future Radio Continuum Surveys and the Multi-Tracer Technique
• Non-local bias in the halo bispectrum with primordial non-Gaussianity
• Exploring KSZ velocity reconstruction with $N$-body simulations and the halo model
• The Power of Locality: Primordial Non-Gaussianity at the Map Level
• Probing Cosmic Origins with CO and [CII] Emission Lines
• Light Fields during Inflation from BOSS and Future Galaxy Surveys
• Taming assembly bias for primordial non-Gaussianity
• Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
• Primordial power spectrum features in phenomenological descriptions of inflation
• Compensated Isocurvature Perturbations in the Galaxy Power Spectrum
• Shot noise in multi-tracer constraints on $f_{\text{NL}}$ and relativistic projections: Power Spectrum
• Primordial non-Gaussianity with Angular correlation function: Integral constraint and validation for DES
• Single-Field Inflation and the Local Ansatz: Distinguishability and Consistency
• Validating galaxy clustering models with Fixed & Paired and Matched-ICs simulations: application to Primordial Non-Gaussianities
• Exact Modeling of Power Spectrum Multipole through Spherical Fourier-Bessel Basis
• Nonminimally Assisted Inflation: A General Analysis
• All-sky angular power spectra from cleaned WISE$\times$SuperCOSMOS galaxy number counts
• Double inflation via non-minimally coupled spectator
• Contributions from primordial non-Gaussianity and General Relativity to the galaxy power spectrum
• Separating Angular and Radial Modes with Spherical-Fourier Bessel Power Spectrum on All Scales and Implications for Systematics Mitigation
• Modes of the Dark Ages 21cm field accessible to a lunar radio interferometer
• Largest scales from the largest galaxy surveys: the pseudo Karhunen-Loève method
• Generalized local ansatz for scale-dependent primordial non-Gaussianities and future galaxy surveys
• A revisited Correction to the Halo Mass Function for local-type Primordial non-Gaussianity