Planck Trispectrum Constraints on Primordial Non-Gaussianity at Cubic Order

Abstract

Non-Gaussianity of the primordial density perturbations provides an important measure to constrain models of inflation. At cubic order the non-Gaussianity is captured by two parameters ${\tau }_{\mathrm{NL}}$ and $g_{\mathrm{NL}}$ that determine the amplitude of the density perturbation trispectrum. Here we report measurements of the kurtosis power spectra of the cosmic microwave background (CMB) temperature as mapped by Planck by making use of correlations between square temperature-square temperature and cubic temperature-temperature anisotropies. In combination with noise simulations, we find the best joint estimates to be ${\tau }_{\mathrm{NL}}=0.3\pm 0.9\times 10^4$ and $g_{\mathrm{NL}}=-1.2\pm 2.8\times 10^5$. If ${\tau }_{\mathrm{NL}}=0$, we find $g_{\mathrm{NL}}=-1.3\pm 1.8\times 10^5$.

6 pages, 4 figures

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Cited by in corpus (12)

• Planck 2015 results. XVII. Constraints on primordial non-Gaussianity
• The Observational Status of Cosmic Inflation after Planck
• Joint analysis of anisotropic power spectrum, bispectrum and trispectrum: application to N-body simulations
• Matter trispectrum: theoretical modelling and comparison to N-body simulations
• Primordial trispectra and CMB spectral distortions
• Scale-dependent non-Gaussianity and the CMB Power Asymmetry
• General and consistent statistics for cosmological observations
• Angular dependence of primordial trispectra and CMB spectral distortions
• Integrated trispectrum detection from BOSS DR12 NGC CMASS
• Constraints on ${\tau }_{\mathrm{NL}}$ from Planck temperature and polarization
• Statistical anisotropies in temperature and polarization fluctuations from a scale-dependent trispectrum
• The Size of Local Bispectrum and Trispectrum in a Non-Minimal Inflation