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Related papers: A low CMB variance in the WMAP data

200 papers

Several accurate analyses have revealed a statistically significant North-South ecliptic asymmetry in the large-angle correlations strength of the Cosmic Microwave Background (CMB) radiation temperature field data from the Wilkinson…

Astrophysics · Physics 2009-02-23 Armando Bernui

We devise a measure n(r) to quantify a robust feature in the coherent cosmic perturbations, namely the narrowness of the first peak in the power spectrum of the Cosmic Microwave Background (CMB) anisotropy. A maximum-likelihood analysis…

Astrophysics · Physics 2007-05-23 Jiun-Huei Proty Wu

The quadrupole power of cosmic microwave background (CMB) temperature anisotropies seen in the WMAP data is puzzlingly low. In this paper we demonstrate that Minimum Variance Optimization (MVO), a technique used by many authors (including…

Astrophysics · Physics 2009-03-18 Lung-Yih Chiang , Pavel D. Naselsky , Peter Coles

Recent measurements of the temperature fluctuations of the cosmic microwave background (CMB) radiation from the WMAP satellite provide indication of a non-Gaussian behavior. Although the observed feature is small, it is detectable and…

Astrophysics · Physics 2008-11-26 Armando Bernui , Constantino Tsallis , Thyrso Villela

ABRIDGED: We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the WMAP CMB foreground reduced, temperature maps, and cross-channel difference maps. We divide the sky into regions of varying…

Astrophysics · Physics 2009-06-23 Bartosz Lew

I discuss whether the standard cosmological models fit the WMAP data well enough to justify parameter estimation with standard assumptions. The observed quadrupole is low (but has significant foreground uncertainty) and drives weak evidence…

Astrophysics · Physics 2017-08-23 Antony Lewis

Using a nonparametric function estimation methodology, we present a comparative analysis of the WMAP 1-, 3-, 5-, and 7-year data releases for the CMB angular power spectrum with respect to the following key questions: (a) How well is the…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-10 Amir Aghamousa , Mihir Arjunwadkar , Tarun Souradeep

We analyze WMAP 3 year data using the one-point distribution functions to probe the non-Gaussianity in the Cosmic Microwave Background (CMB) Anisotropy data. Computer simulations are performed to determine the uncertainties of the results.…

Astrophysics · Physics 2007-10-16 E. Jeong , G. F. Smoot

Cosmic Microwave Background (CMB) anisotropies that result from quantum fluctuations during inflation are explored and the impact of their ``cosmic variance'' on the ability to use existing data to probe inflationary models is studied. We…

Astrophysics · Physics 2016-08-30 Martin White , Lawrence M. Krauss , Joseph Silk

Two groups [3,4] have confirmed the results of our paper concerning the actual existence of low variance circles in the cosmic microwave background (CMB) sky. They also point out that the effect does not contradict the LCDM model - a matter…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-08 V. G. Gurzadyan , R. Penrose

The first-year WMAP data, in combination with any one of a number of other cosmic probes, show that we live in a flat \Lambda-dominated CDM universe with \Omega_m ~ 0.27 and \Omega_\Lambda ~ 0.73. In this model the late-time action of the…

We present the final nine-year maps and basic results from the WMAP mission. We provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are…

The first observations of the cosmic microwave background (CMB) from NASA's \emph{Wilkinson Microwave Anisotropy Probe} (WMAP) led to finding `alignment' anomalies not expected from fluctuations in the isotropic cosmological model. We study…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Sanjeet Kumar Patel , Pavan Kumar Aluri , John P. Ralston

Since the very first observations, the Cosmic Microwave Background (CMB) has revealed on large-scales unexpected features known as anomalies, which challenge the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. One…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-24 Giacomo Galloni , Mario Ballardini , Nicola Bartolo , Alessandro Gruppuso , Luca Pagano , Angelo Ricciardone

The lack of power at large angular scales in the CMB temperature anisotropy pattern is a feature known to depend on the size of the Galactic mask. Not only the large scale anisotropy power in the CMB is lower than the best-fit $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-11 U. Natale , A. Gruppuso , D. Molinari , P. Natoli

We systematically analyze the primordial non-Gaussianity estimator used by the Wilkinson Microwave Anisotropy Probe (WMAP) science team with the basic ideas of estimation theory in order to see if the limited Cosmic Microwave Background…

Astrophysics · Physics 2009-11-10 Daniel Babich

Since WMAP and Planck some anomalous features appeared in the Cosmic Microwave Background (CMB) large-angle anisotropy, the so-called anomalies. One of these is the hemispherical power asymmetry, i.e. a difference in the average power on…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-06 Giacomo Galloni , Nicola Bartolo , Sabino Matarrese , Marina Migliaccio , Angelo Ricciardone , Nicola Vittorio

Accurate measurements of angular power spectrum of Cosmic Microwave Background (CMB) radiation has lead to marked improvement in the estimates of different cosmological parameters. This has required removal of foreground contamination as…

Astrophysics · Physics 2009-11-13 Rajib Saha , Pankaj Jain , Tarun Souradeep

Several unexpected features have been observed in the microwave sky at large angular scales, both by WMAP an by Planck. Among those features is a lack of both variance and correlation on the largest angular scales, alignment of the lowest…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Dominik J. Schwarz , Craig J. Copi , Dragan Huterer , Glenn D. Starkman

Using a Gibbs sampling algorithm for joint CMB estimation and component separation, we compute the large-scale CMB and foreground posteriors of the 3-yr WMAP temperature data. Our parametric data model includes the cosmological CMB signal…

Astrophysics · Physics 2010-11-11 H. K. Eriksen , C. Dickinson , J. B. Jewell , A. J. Banday , K. M. Gorski , C. R. Lawrence