English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/110614
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Planck 2013 results. XXIII. Isotropy and statistics of the CMB

AuthorsMartínez-González, Enrique ; Barreiro, R. Belén ; Bonavera, Laura ; Curto, Andrés ; Diego, José María ; González-Nuevo, J. ; Herranz, D. ; López-Caniego, M. ; Rebolo López, Rafael; Toffolatti, L. ; Vielva, P. ; Planck Collaboration
KeywordsCosmology: miscellaneous
Cosmic background radiation
Cosmology: observations
Issue Date2014
PublisherEDP Sciences
CitationAstronomy and Astrophysics 571: A23 (2014)
AbstractThe two fundamental assumptions of the standard cosmological model-that the initial fluctuations are statistically isotropic and Gaussian-are rigorously tested using maps of the cosmic microwave background (CMB) anisotropy from the Planck satellite. The detailed results are based on studies of four independent estimates of the CMB that are compared to simulations using a fiducial ΛCDM model and incorporating essential aspects of the Planck measurement process. Deviations from isotropy have been found and demonstrated to be robust against component separation algorithm, mask choice, and frequency dependence. Many of these anomalies were previously observed in the WMAP data, and are now confirmed at similar levels of significance (about 3σ). However, we find little evidence of non-Gaussianity, with the exception of a few statistical signatures that seem to be associated with specific anomalies. In particular, we find that the quadrupole-octopole alignment is also connected to a low observed variance in the CMB signal. A power asymmetry is now found to persist on scales corresponding to about â.,> = 600 and can be described in the low-â.,> regime by a phenomenological dipole modulation model. However, any primordial power asymmetry is strongly scale-dependent and does not extend to arbitrarily small angular scales. Finally, it is plausible that some of these features may be reflected in the angular power spectrum of the data, which shows a deficit of power on similar scales. Indeed, when the power spectra of two hemispheres defined by a preferred direction are considered separately, one shows evidence of a deficit in power, while its opposite contains oscillations between odd and even modes that may be related to the parity violation and phase correlations also detected in the data. Although these analyses represent a step forward in building an understanding of the anomalies, a satisfactory explanation based on physically motivated models is still lacking.
Publisher version (URL)http://dx.doi.org/10.1051/0004-6361/201321534
URIhttp://hdl.handle.net/10261/110614
DOI10.1051/0004-6361/201321534
Identifiersdoi: 10.1051/0004-6361/201321534
issn: 0004-637X
e-issn: 1432-0746
Appears in Collections:(IFCA) Artículos
Files in This Item:
File Description SizeFormat 
XXIII. Isotropy.pdf8,01 MBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.