The bispectrum of redshifted 21-cm fluctuations from the dark ages

Abstract

Brightness-temperature fluctuations in the redshifted 21-cm background from the cosmic dark ages are generated by irregularities in the gas-density distribution and can then be used to determine the statistical properties of density fluctuations in the early Universe. We first derive the most general expansion of brightness-temperature fluctuations up to second order in terms of all the possible sources of spatial fluctuations. We then focus on the three-point statistics and compute the angular bispectrum of brightness-temperature fluctuations generated prior to the epoch of hydrogen reionization. For simplicity, we neglect redshift-space distortions. We find that low-frequency radio experiments with arcmin angular resolution can easily detect non-Gaussianity produced by non-linear gravity with high signal-to-noise ratio. The bispectrum thus provides a unique test of the gravitational instability scenario for structure formation, and can be used to measure the cosmological parameters. Detecting the signature of primordial non-Gaussianity produced during or right after an inflationary period is more challenging but still possible. An ideal experiment limited by cosmic variance only and with an angular resolution of a few arcsec has the potential to detect primordial non-Gaussianity with a non-linearity parameter of f_NL ~ 1. Additional sources of error as weak lensing and an imperfect foreground subtraction could severely hamper the detection of primordial non-Gaussianity which will benefit from the use of optimal estimators combined with tomographic techniques.

arXiv comment15 pages, 4 figures, revised version accepted for publication in ApJ (contains an improved discussion of gas temperature fluctuations)

References in corpus (21)

• Eternal Black Holes in AdS
• Non-Gaussianity from Inflation: Theory and Observations
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• 21-cm Tomography of the Intergalactic Medium at High Redshift
• Second-Order Cosmological Perturbations from Inflation
• The Three--Point Correlation Function of the Cosmic Microwave Background in Inflationary Models
• How exactly did the Universe become neutral?
• Large-scale structure, the cosmic microwave background, and primordial non-gaussianity
• Measuring the Small-Scale Power Spectrum of Cosmic Density Fluctuations Through 21 cm Tomography Prior to the Epoch of Structure Formation
• The Reionization of the Universe by the First Stars and Quasars
• The CMBR fluctuations from HI perturbations prior to reionization
• Probing Primordial Non-Gaussianity with Large-Scale Structure
• The Microwave Background Bispectrum, Paper I: Basic Formalism
• CMB Anisotropies at Second-Order II: Analytical Approach
• Tests for primordial non-Gaussianity
• The Angular Bispectrum of The Cosmic Microwave Background
• Probing the bispectrum at high redshifts using 21 cm HI observations
• Projected bispectrum in spherical harmonics and its application to angular galaxy catalogues
• Large-Scale Non-Gaussianities in the 21 cm Background Anisotropies From the Era of Reionization
• Signatures of Primordial Non-Gaussianity in the Large-Scale Structure of the Universe
• Weak Gravitational Lensing of High-Redshift 21 cm Power Spectra

Cited by in corpus (81)

• Cosmology and Fundamental Physics with the Euclid Satellite
• 21-cm cosmology
• Cosmology and fundamental physics with the Euclid satellite
• Fundamental Physics with the Square Kilometre Array
• The Physics of the Intergalactic Medium
• Effects of Scale-Dependent Non-Gaussianity on Cosmological Structures
• Halo mass function and scale-dependent bias from N-body simulations with non-Gaussian initial conditions
• Primordial non-Gaussianity and Bispectrum Measurements in the Cosmic Microwave Background and Large-Scale Structure
• The 21cm angular-power spectrum from the dark ages
• Non-Gaussian halo bias and future galaxy surveys
• Detectability of the effect of Inflationary non-Gaussianity on halo bias
• Prospects for Cosmological Collider Physics
• Primordial non-gaussianity from the bispectrum of 21-cm fluctuations in the dark ages
• Forecasts on the Dark Energy and Primordial Non-Gaussianity Observations with the Tianlai Cylinder Array
• N-body simulations with generic non-Gaussian initial conditions I: Power Spectrum and halo mass function
• Evolution of Massive Haloes in non-Gaussian Scenarios
• A new light on 21 cm intensity fluctuations from the dark ages
• The Future of Primordial Features with 21 cm Tomography
• 21cm-line bispectrum as method to probe Cosmic Dawn and Epoch of Reionization
• Large Spin-2 Signals at the Cosmological Collider
• The 21 cm signal and the interplay between dark matter annihilations and astrophysical processes
• The atomic Hydrogen content of the post-reionization Universe
• Primordial non-Gaussianity in the large scale structure of the Universe
• Signatures of primordial black holes as seeds of supermassive black holes
• Temperature and Polarization CMB Maps from Primordial non-Gaussianities of the Local Type
• Inflation and Early Dark Energy with a Stage II Hydrogen Intensity Mapping Experiment
• The trispectrum of 21-cm background anisotropies as a probe of primordial non-Gaussianity
• Cosmological Parameters Degeneracies and Non-Gaussian Halo Bias
• Cosmological perturbation theory for baryons and dark matter I: one-loop corrections in the RPT framework
• Sensitivity for 21cm Bispectrum from Epoch of Reionization
• On CMB B-Mode Non-Gaussianity
• Recovering the HII region size statistics from 21-cm tomography
• Non-linear Redshift-Space Power Spectra
• The Hunt for Primordial Interactions in the Large Scale Structures of the Universe
• The clustering of galaxies and galaxy clusters: constraints on primordial non-Gaussianity from future wide-field surveys
• Imprints of primordial non-Gaussianity on the number counts of cosmic shear peaks
• Studying 21cm power spectrum with one-point statistics
• Prospects for precision cosmology with the 21 cm signal from the dark ages
• The clustering of galaxy clusters in cosmological models with non-Gaussian initial conditions: Predictions for future surveys
• Primordial non-Gaussianity from the 21 cm Power Spectrum during the Epoch of Reionization
• Oscillations in the Primordial Bispectrum: Mode Expansion
• Cosmic (super)string constraints from 21 cm radiation
• Studying the morphology of HI isodensity surfaces during reionization using Shapefinders and percolation analysis
• Constraining Curvatonic Reheating
• The effects of primordial non-Gaussianity on the cosmological reionization
• Primordial trispectra and CMB spectral distortions
• Counts of high-redshift GRBs as probe of primordial non-Gaussianities
• Violation of statistical isotropy and homogeneity in the 21-cm power spectrum
• The HI intensity mapping bispectrum including observational effects
• A numerical study of the effects of primordial non-Gaussianities on weak lensing statistics
• General relativistic corrections and non-Gaussianity in large scale structure
• The Dark Ages' 21-cm Trispectrum
• Small-scale primordial fluctuations in the 21cm Dark Ages signal
• Angular dependence of primordial trispectra and CMB spectral distortions
• The 21cm radiation from minihalos as a probe of small primordial non-Gaussianity
• Modelling the post-reionization neutral hydrogen ($\mathrm{HI}$) 21-cm bispectrum
• Impact of dark matter models on the EoR 21-cm signal bispectrum
• Exploring the cosmic dawn and epoch of reionization with 21cm line
• The contribution of the IGM and minihalos to the 21 cm signal of reionization
• On the Trispectrum of Galileon Inflation
• Enlightening the dark ages with dark matter
• Probing the primordial Universe with 21-cm line from cosmic dawn/epoch of reionization
• Probing a panoply of curvaton-decay scenarios using CMB data
• Multi-variate joint PDF for non-Gaussianities: exact formulation and generic approximations
• The 21cm Power Spectrum and the Shapes of Non-Gaussianity
• Detecting the integrated Sachs-Wolfe effect with high-redshift 21-cm surveys
• Cosmic mysteries and the hydrogen 21-cm line: bridging the gap with lunar observations
• Testing the scale-dependent hemispherical asymmetry with the 21-cm power spectrum from the epoch of reionization
• The gravitational and lensing-ISW bispectrum of 21cm radiation
• Supergravity, $\alpha$-attractors and primordial non-Gaussianity
• The Trispectrum in the Effective Theory of Inflation with Galilean symmetry
• Cosmic shear statistics in cosmologies with non-Gaussian initial conditions
• The effect of primordial non-Gaussianity on the skeleton of cosmic shear maps
• Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion
• The ultimate frontier of 21cm cosmology
• Relics of spatial curvature in the primordial non-gaussianity
• Studying neutral hydrogen structures during the epoch of reionization using fractal dimensions
• Perspectives on fundamental cosmology from Low Earth Orbit and the Moon
• Modes of the Dark Ages 21cm field accessible to a lunar radio interferometer
• Testing the growth of cosmic structures during the Dark Ages
• Testing Inflationary Cosmology