On the non-Gaussianity from Recombination

Abstract

The non-linear effects operating at the recombination epoch generate a non-Gaussian signal in the CMB anisotropies. Such a contribution is relevant because it represents a major part of the second-order radiation transfer function which must be determined in order to have a complete control of both the primordial and non-primordial part of non-Gaussianity in the CMB anisotropies. We provide an estimate of the level of non-Gaussianity in the CMB arising from the recombination epoch which shows up mainly in the equilateral configuration. We find that it causes a contamination to the possible measurement of the equilateral primordial bispectrum shifting the minimum detectable value of the non-Gaussian parameter f^equil_NL by Delta f^equil_NL= O(10) for an experiment like Planck.

LaTeX file; 11 pages. v2: Typos corrected; references added; comments about the effective non-linearity parameter added in Sec. IV; comments added in the conclusions of Sec. IV. v3: References added; some clarifications added as footnotes 4 and 6, and in Sec. 3. Matches version accepted for publication in JCAP

References in corpus (39)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Particle Physics Models of Inflation and the Cosmological Density Perturbation
• Non-Gaussianity from Inflation: Theory and Observations
• DBI in the Sky
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• Small Scale Cosmological Perturbations: An Analytic Approach
• The primordial density perturbation in the curvaton scenario
• Second-Order Cosmological Perturbations from Inflation
• Ghost Inflation
• A new mechanism for generating density perturbations from inflation
• The shape of non-Gaussianities
• Weak Lensing of the CMB: A Harmonic Approach
• Limits on non-Gaussianities from WMAP data
• Non-Gaussianity in multi-field inflation
• Non-Gaussianities in two-field inflation
• On Non-Gaussianity in the Curvaton Scenario
• Non-Gaussianity from Inflation
• Generating the curvature perturbation at the end of inflation
• Cosmological Perturbations From Inhomogeneous Reheating, Freeze-Out, and Mass Domination
• The Microwave Background Bispectrum, Paper II: A Probe of the Low Redshift Universe
• The Damping Tail of CMB Anisotropies
• Primordial Bispectrum Information from CMB Polarization
• CMB Anisotropies at Second Order I
• CMB Anisotropies at Second-Order II: Analytical Approach
• Testing Primordial Non-Gaussianity in CMB Anisotropies
• CMB 3-point functions generated by non-linearities at recombination
• On the generation of density perturbations at the end of inflation
• Generating the Curvature Perturbation at the End of Inflation in String Theory
• Curvature Perturbations from Broken Symmetries
• Impact of Secondary non-Gaussianities on the Search for Primordial Non-Gaussianity with CMB Maps
• Cosmic microwave background bispectrum on small angular scales
• Evolution of Cosmological Perturbations during Reheating
• Crinkles in the last scattering surface: Non-Gaussianity from inhomogeneous recombination
• Non-Gaussianity from Broken Symmetries
• Preheating curvature perturbations with a coupled curvaton
• Gauge invariant Boltzmann equation and the fluid limit
• Point Source Contamination in CMB Non-Gaussianity Analyses
• Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity

Cited by in corpus (29)

• Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity
• Non-Gaussianities in Single Field Inflation and their Optimal Limits from the WMAP 5-year Data
• Hunting for Primordial Non-Gaussianity in the Cosmic Microwave Background
• Planck pre-launch status: the Planck-LFI programme
• The cosmic microwave background temperature bispectrum from scalar perturbations induced by primordial magnetic fields
• The cosmic microwave background bispectrum from the non-linear evolution of the cosmological perturbations
• CMB lensing and primordial non-Gaussianity
• The CMB bispectrum in the squeezed limit
• Sachs-Wolfe at second order: the CMB bispectrum on large angular scales
• CMB anisotropies at second order III: bispectrum from products of the first-order perturbations
• Detecting Bispectral Acoustic Oscillations from Inflation Using a New Flexible Estimator
• The CMB bispectrum from recombination
• Non-Gaussianity in the Cosmic Microwave Background Anisotropies at Recombination in the Squeezed limit
• Non-Gaussianity and the CMB Bispectrum: confusion between Primordial and Lensing-Rees Sciama contribution?
• Analytic formulae of the CMB bispectra generated from non-Gaussianity in the tensor and vector perturbations
• Strongly Scale-dependent Non-Gaussianity
• Non-Gaussianities from Perturbing Recombination
• Fundamental limits on constraining primordial non-Gaussianity
• Minimizing gravitational lensing contributions to the primordial bispectrum covariance
• A numerical study of the effects of primordial non-Gaussianities on weak lensing statistics
• Geodesic "curve"-of-sight formulae for the cosmic microwave background: a unified treatment of redshift, time delay, and lensing
• Trispectrum versus Bispectrum in Single-Field Inflation
• Non-Gaussian CMB and LSS statistics beyond polyspectra
• Unified approach to secondary effects on the CMB B-mode polarization
• Statistics of the excursion sets in models with local primordial non-Gaussianity
• The primordial information content of Rayleigh Anisotropies
• Relics of spatial curvature in the primordial non-gaussianity
• On non-linear CMB temperature anisotropy from gravitational perturbations
• Probing Dark Matter Isocurvature with Primordial Non-Gaussianity