Data di Pubblicazione:
2014
Abstract:
The Planck nominal mission cosmic microwave background (CMB) maps yield
unprecedented constraints on primordial non-Gaussianity (NG). Using
three optimal bispectrum estimators, separable template-fitting (KSW),
binned, and modal, we obtain consistent values for the primordial local,
equilateral, and orthogonal bispectrum amplitudes, quoting as our final
result fNLlocal = 2.7 � 5.8,
fNLequil = -42 � 75, and
fNLorth = -25 � 39 (68% CL statistical).
Non-Gaussianity is detected in the data; using skew-Cl
statistics we find a nonzero bispectrum from residual point sources, and
the integrated-Sachs-Wolfe-lensing bispectrum at a level expected in the
LambdaCDM scenario. The results are based on comprehensive
cross-validation of these estimators on Gaussian and non-Gaussian
simulations, are stable across component separation techniques, pass an
extensive suite of tests, and are confirmed by skew-Cl,
wavelet bispectrum and Minkowski functional estimators. Beyond estimates
of individual shape amplitudes, we present model-independent,
three-dimensional reconstructions of the Planck CMB bispectrum and thus
derive constraints on early-Universe scenarios that generate primordial
NG, including general single-field models of inflation, excited initial
states (non-Bunch-Davies vacua), and directionally-dependent vector
models. We provide an initial survey of scale-dependent feature and
resonance models. These results bound both general single-field and
multi-field model parameter ranges, such as the speed of sound,
cs >= 0.02 (95% CL), in an effective field theory
parametrization, and the curvaton decay fraction rD >= 0.15
(95% CL). The Planck data significantly limit the viable parameter space
of the ekpyrotic/cyclic scenarios. The amplitude of the four-point
function in the local model tauNL< 2800 (95% CL). Taken
together, these constraints represent the highest precision tests to
date of physical mechanisms for the origin of cosmic structure.
unprecedented constraints on primordial non-Gaussianity (NG). Using
three optimal bispectrum estimators, separable template-fitting (KSW),
binned, and modal, we obtain consistent values for the primordial local,
equilateral, and orthogonal bispectrum amplitudes, quoting as our final
result fNLlocal = 2.7 � 5.8,
fNLequil = -42 � 75, and
fNLorth = -25 � 39 (68% CL statistical).
Non-Gaussianity is detected in the data; using skew-Cl
statistics we find a nonzero bispectrum from residual point sources, and
the integrated-Sachs-Wolfe-lensing bispectrum at a level expected in the
LambdaCDM scenario. The results are based on comprehensive
cross-validation of these estimators on Gaussian and non-Gaussian
simulations, are stable across component separation techniques, pass an
extensive suite of tests, and are confirmed by skew-Cl,
wavelet bispectrum and Minkowski functional estimators. Beyond estimates
of individual shape amplitudes, we present model-independent,
three-dimensional reconstructions of the Planck CMB bispectrum and thus
derive constraints on early-Universe scenarios that generate primordial
NG, including general single-field models of inflation, excited initial
states (non-Bunch-Davies vacua), and directionally-dependent vector
models. We provide an initial survey of scale-dependent feature and
resonance models. These results bound both general single-field and
multi-field model parameter ranges, such as the speed of sound,
cs >= 0.02 (95% CL), in an effective field theory
parametrization, and the curvaton decay fraction rD >= 0.15
(95% CL). The Planck data significantly limit the viable parameter space
of the ekpyrotic/cyclic scenarios. The amplitude of the four-point
function in the local model tauNL< 2800 (95% CL). Taken
together, these constraints represent the highest precision tests to
date of physical mechanisms for the origin of cosmic structure.
Tipologia CRIS:
1.1 Articolo in rivista
Keywords:
cosmic background radiation; cosmology: observations; cosmology: theory; early Universe; inflation; methods: data analysis
Elenco autori:
P., Collaboration; P. A., R.; N., Aghanim; C., Armitage Caplan; M., Arnaud; M., Ashdown; F., Atrio Barandela; J., Aumont; C., Baccigalupi; A. J., Banday; R. B., Barreiro; J. G., Bartlett; N., Bartolo; E., Battaner; K., Benabed; A., Beno�t; A., Benoit L�vy; J., Bernard; M., Bersanelli; P., Bielewicz; J., Bobin; J. J., Bock; A., Bonaldi; L., Bonavera; J. R., Bond; J., Borrill; F. R., Bouchet; M., Bridges; M., Bucher; C., Burigana; R. C., Butler; J., Cardoso; A., Catalano; A., Challinor; A., Chamballu; H. C., Chiang; L., Chiang; P. R., Christensen; S., Church; D. L., Clements; S., Colombi; L. P., L.; F., Couchot; A., Coulais; B. P., Crill; A., Curto; F., Cuttaia; L., Danese; R. D., Davies; R. J., Davis; P. d., Bernardis; A. d., Rosa; G. d., Zotti; J., Delabrouille; J., Delouis; F., D�sert; J. M., Diego; H., Dole; S., Donzelli; O., Dor�; M., Douspis; A., Ducout; J., Dunkley; X., Dupac; G., Efstathiou; F., Elsner; T. A., En�lin; H. K., Eriksen; J., Fergusson; F., Finelli; O., Forni; M., Frailis; E., Franceschi; S., Galeotta; K., Ganga; M., Giard; Y., Giraud H�raud; J., Gonz�lez Nuevo; K. M., G�rski; S., Gratton; A., Gregorio; A., Gruppuso; F. K., Hansen; D., Hanson; D., Harrison; A., Heavens; S., Henrot Versill�; C., Hern�ndez Monteagudo; D., Herranz; S. R., Hildebrandt; E., Hivon; M., Hobson; W. A., Holmes; A., Hornstrup; W., Hovest; K. M., Huffenberger; A. H., Jaffe; T. R., Jaffe; W. C., Jones; M., Juvela; E., Keih�nen; R., Keskitalo; T. S., Kisner; J., Knoche; L., Knox; M., Kunz; H., Kurki Suonio; F., Lacasa; G., Lagache; A., L�hteenm�ki; J., Lamarre; A., Lasenby; R. J., Laureijs; C. R., Lawrence; J. P., Leahy; R., Leonardi; J., Lesgourgues; A., Lewis; M., Liguori; P. B., Lilje; M., Linden V�rnle; M., L�pez Caniego; P. M., Lubin; J. F., Mac�as P�rez; B., Maffei; D., Maino; N., Mandolesi; A., Mangilli; D., Marinucci; M., Maris; D. J., Marshall; P. G., Martin; E., Mart�nez Gonz�lez; S., Masi; M., Massardi; S., Matarrese; F., Matthai; P., Mazzotta; P. R., Meinhold; A., Melchiorri; L., Mendes; A., Mennella; M., Migliaccio; S., Mitra; M., Miville Desch�nes; A., Moneti; L., Montier; G., Morgante; D., Mortlock; A., Moss; D., Munshi; J. A., Murphy; P., Naselsky; P., Natoli; C. B., Netterfield; H. U., N�rgaard Nielsen; F., Noviello; D., Novikov; I., Novikov; S., Osborne; C. A., Oxborrow; F., Paci; L., Pagano; F., Pajot; D., Paoletti; F., Pasian; G., Patanchon; H. V., Peiris; O., Perdereau; L., Perotto; F., Perrotta; F., Piacentini; M., Piat; E., Pierpaoli; D., Pietrobon; S., Plaszczynski; E., Pointecouteau; G., Polenta; N., Ponthieu; L., Popa; T., Poutanen; G. W., Pratt; G., Pr�zeau; S., Prunet; J., Puget; J. P., Rachen; B., Racine; R., Rebolo; M., Reinecke; M., Remazeilles; C., Renault; A., Renzi; S., Ricciardi; T., Riller; I., Ristorcelli; G., Rocha; C., Rosset; G., Roudier; Mart�n, J. A. Rubi�o.; B., Rusholme; M., Sandri; D., Santos; G., Savini; D., Scott; M. D., Seiffert; E. P., S.; K., Smith; L. D., Spencer; J., Starck; V., Stolyarov; R., Stompor; R., Sudiwala; R., Sunyaev; F., Sureau; P., Sutter; D., Sutton; A., Suur Uski; J., Sygnet; J. A., Tauber; D., Tavagnacco; Terenzi, Luca; L., Toffolatti; M., Tomasi; M., Tristram; M., Tucci; J., Tuovinen; L., Valenziano; J., Valiviita; B. V., Tent; J., Varis; P., Vielva; F., Villa; N., Vittorio; L. A., Wade; B. D., Wandelt; M., White; S. D., M.; D., Yvon; A., Zacchei; A., Zonca
Link alla scheda completa:
Pubblicato in: