10-1051-0004-6361-201525836.pdf (15.26 MB)
Planck 2015 results. XVII. Constraints on primordial non-Gaussianity
journal contribution
posted on 2023-06-09, 04:42 authored by Antony LewisAntony Lewis, Dipak MunshiDipak Munshi, et al. The Planck CollaborationThe Planck full mission cosmic microwave background(CMB) temperature and E-mode polarization maps are analysed to obtain constraints on primordial non-Gaussianity(NG). Using three classes of optimal bispectrum estimators - separable template-fitting (KSW), binned, and modal - we obtain consistent values for the local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result from temperature alone fNL^local=2.5+\-5.7, fNL^equil=-16+\-70 and fNL^ortho=-34+\-33(68%CL). Combining temperature and polarization data we obtain fNL^local=0.8+\-5.0, fNL^equil=-4+\-43 and fNL^ortho=-26+\-21 (68%CL). The results are based on cross-validation of these estimators on simulations, are stable across component separation techniques, pass an extensive suite of tests, and are consistent with Minkowski functionals based measurements. The effect of time-domain de-glitching systematics on the bispectrum is negligible. In spite of these test outcomes we conservatively label the results including polarization data as preliminary, owing to a known mismatch of the noise model in simulations and the data. Beyond fNL estimates, we present model-independent reconstructions of the CMB bispectrum and derive constraints on early universe scenarios that generate NG, including general single-field and axion inflation, initial state modifications, parity-violating tensor bispectra, and directionally dependent vector models. We also present a wide survey of scale-dependent oscillatory bispectra, and we look for isocurvature NG. Our constraint on the local primordial trispectrum amplitude is gNL^local=(-9.0+\-7.7)x10^4 (68%CL), and we perform an analysis of additional trispectrum shapes. The global picture is one of consistency with the premises of the LambdaCDM cosmology, namely that the structure we observe today was sourced by adiabatic, passive, Gaussian, and primordial seed perturbations.[abridged]
Funding
Astrophysics and Cosmology - Sussex Consolidated Grant; G1291; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/L000652/1
Precision cosmological parameters : CosmoPars; G1365; EUROPEAN UNION; 616170 ERC-2013-CoG
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Astronomy and AstrophysicsISSN
0004-6361Publisher
EDP SciencesExternal DOI
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A17Volume
594Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Astronomy Centre Publications
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- Yes
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2017-01-12First Open Access (FOA) Date
2017-01-12First Compliant Deposit (FCD) Date
2017-01-12Usage metrics
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