Probing small-scale non-Gaussianity from anisotropies in acoustic reheating

Abstract

We give new constraints on small-scale non-Gaussianity of primordial curvature perturbations by the use of anisotropies in acoustic reheating. Mixing of local thermal or local kinetic equilibrium systems with different temperatures yields a locally averaged temperature rise, which is proportional to the square of temperature perturbations damping in the photon diffusion scale. Such secondary temperature perturbations are indistinguishable from the standard temperature perturbations linearly coming from primordial curvature perturbations and hence should be subdominant compared to the standard ones. We show that small-scale higher order correlation functions (connected non-Gaussian and disconnected Gaussian parts) of primordial curvature perturbations can be probed by investigating auto power spectrum of the generated secondary perturbations and the cross power spectrum with the standard perturbations. This is simply because these power spectra come from higher order correlation functions of primordial curvature perturbations with non-linear parameters such as $f_{\mathrm{NL}}$ and ${\tau }_{\mathrm{NL}}$ since secondary temperature perturbations are second order effects. Thus, the observational results $l(l+1)C_l^{TT}\simeq 6\times 10^{-10}$ at large scales give a robust and universal upper bound on small-scale non-Gaussianities of primordial curvature perturbations.

arXiv comment17 pages, 3 figures, prepared for submission to JCAP

References in corpus (31)

• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Cosmological Perturbation Theory in the Synchronous vs. Conformal Newtonian Gauge
• Cosmological Perturbation Theory in the Synchronous and Conformal Newtonian Gauges
• The Cosmic Microwave Background Spectrum from the Full COBE/FIRAS Data Set
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• Small Scale Cosmological Perturbations: An Analytic Approach
• The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations
• Probing the inflaton: Small-scale power spectrum constraints from measurements of the CMB energy spectrum
• Cosmic Microwave Background Polarization
• CMB at 2x2 order: the dissipation of primordial acoustic waves and the observable part of the associated energy release
• Primordial trispectrum from inflation
• Generalised constraints on the curvature perturbation from primordial black holes
• Power Spectrum Constraints from Spectral Distortions in the Cosmic Microwave Background
• Primordial black holes as a tool for constraining non-Gaussianity
• Constraining Running Non-Gaussianity
• CMB Anisotropies at Second Order I
• Silk damping at a redshift of a billion: a new limit on small-scale adiabatic perturbations
• A New Window on Primordial non-Gaussianity
• CMB Anisotropies at Second-Order II: Analytical Approach
• Beyond y and μ: the shape of the CMB spectral distortions in the intermediate epoch, 1.5x10^4 < z < 2x10^5
• Mixing of blackbodies: entropy production and dissipation of sound waves in the early Universe
• Creation of the CMB spectrum: precise analytic solutions for the blackbody photosphere
• Reheating the Universe Once More: The Dissipation of Acoustic Waves as a Novel Probe of Primordial Inhomogeneities on Even Smaller Scales
• Superposition of blackbodies and the dipole anisotropy: A possibility to calibrate CMB experiments
• Forecasts for CMB μ- and i-type spectral distortion constraints on the primordial power spectrum on scales 8 < k < 10^4 Mpc^-1 with the future Pixie-like experiments
• The CMB bispectrum from recombination
• Testing Inflation and Curvaton Scenarios with CMB Distortions
• A joint study of early and late spectral distortions of the cosmic microwave background and of the millimetric foreground
• The double Compton emissivity in a mildly relativistic thermal plasma within the soft photon limit
• The full CMB temperature bispectrum from single-field inflation

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• Secondary isocurvature perturbations from acoustic reheating