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The latest cosmological data seem to indicate a significant deviation from scale invariance of the primordial power spectrum when parameterized either by a power law or by a spectral index with non-zero "running". This deviation, by itself,…

Astrophysics · Physics 2011-05-12 Licia Verde , Hiranya V. Peiris

We study the large-scale angular correlation signatures of the Cosmic Microwave Background (CMB) temperature fluctuations from WMAP data in several spherical cap regions of the celestial sphere, outside the Kp0 or Kp2 cut-sky masks. We…

The Correlated Component Analysis (CCA) allows us to estimate how the different diffuse emissions mix in CMB experiments, exploiting also complementary information from other surveys. It is especially useful to deal with possible additional…

Astrophysics · Physics 2009-01-13 A. Bonaldi , S. Ricciardi , S. Leach , F. Stivoli , C. Baccigalupi , G. De Zotti

We present the first results from a Bayesian analysis of the WMAP first year data using a Gibbs sampling technique. Using two independent, parallel supercomputer codes we analyze the WMAP Q, V and W bands. The analysis results in a full…

Current measurements of the temperature and polarization anisotropy power spectra of the Cosmic Microwave Background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Victor Miralles , Héctor Ramírez , Lotfi Boubekeur

The spectrum and statistics of the cosmic microwave background radiation (CMBR) are investigated under the hypothesis that scale invariance of the primordial density fluctuations should be promoted to full conformal invariance. As in the…

Astrophysics · Physics 2008-11-26 I. Antoniadis , P. O. Mazur , E. Mottola

It has been suggested by Roukema and coworkers (hereafter R04) that the topology of the Universe as probed by the ``matched circles'' method using the first year release of the WMAP CMB data, might be that of the Poincar\'e dodecahedral…

Astrophysics · Physics 2008-04-24 B. S. Lew , B. F. Roukema

I describe briefly the Cosmic Microwave Background (hereafter CMB) physics which explains why high accuracy observations of its spatial structure are a unique observational tool both for the determination of the global cosmological…

Astrophysics · Physics 2007-05-23 Francois R. Bouchet

LWDM (Warm Dark Matter) is progressing impressively.The galactic scale crisis and decline of LCDM+baryons are staggering. The 16th Paris Chalonge Colloquium 2012 combined real cosmological/astrophysical data and hard theory predictive…

General Physics · Physics 2013-07-09 H. J. de Vega , M. C. Falvella , N. G. Sanchez

We use an optimal estimator to study the variance of the WMAP 9 CMB field at low resolution, in both temperature and polarization. Employing realistic Monte Carlo simulation, we find statistically significant deviations from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 A. Gruppuso , P. Natoli , F. Paci , F. Finelli , D. Molinari , A. De Rosa , N. Mandolesi

Since the measurements of COBE/FIRAS in the mid-90's we know that the energy spectrum of the cosmic microwave background (CMB) is extremely close to that of a perfect blackbody at an average temperature T0~2.726K. However, a number of…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-11 Jens Chluba

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Maresuke Shiraishi

Accurate covariance matrices are required for a reliable estimation of cosmological parameters from pseudo-power spectrum estimators. In this work, we focus on the analytical calculation of covariance matrices. We consider the case of…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-08 Étienne Camphuis , Karim Benabed , Silvia Galli , Éric Hivon , Marc Lilley

The frequency spectrum of the cosmic microwave background (CMB) is a relatively untapped source of data which can allow us to peer beyond the surface of last scattering. Small deviations away from a perfect blackbody shape will encode…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-21 Bryce Cyr

Voyage 2050 White Paper highlighting the unique science opportunities using spectral distortions of the cosmic microwave background (CMB). CMB spectral distortions probe many processes throughout the history of the Universe. Precision…

The cosmic microwave background (CMB) temperature maps published by the Wilkinson Microwave Anisotropy Probe (WMAP) team are found to be inconsistent with the differential time-ordered data (TOD), from which the maps are reconstructed. The…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-22 Hao Liu , Ti-Pei Li

We have updated our analysis of the 9-year WMAP data using the collection of polarization maps looking for the presence of additional evidence for a finite 'cosmic ray foreground' for the CMB. We have given special attention to high…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-29 Tadeusz Wibig , Arnold W. Wolfendale

We report here the first full sky component separation and CMB power spectrum estimation using a Wiener filtering technique on simulated data from the upcoming MAP experiment, set to launch in early 2001. The simulations included…

Astrophysics · Physics 2009-10-31 S. Prunet , R. Teyssier , S. T. Scully , F. R. Bouchet , R. Gispert

We extend to large scales a method proposed in previous work that reconstructs non-parametrically the primordial power spectrum from cosmic microwave background data at high resolution. The improvement is necessary to account for the…

Astrophysics · Physics 2009-11-13 Domenico Tocchini-Valentini , Yehuda Hoffman , Joseph Silk

Estimation of the angular power spectrum of the Cosmic Microwave Background (CMB) on a small patch of sky is usually plagued by serious spectral leakage, specially when the map has a hard edge. Even on a full sky map, point source masks can…

Astrophysics · Physics 2009-11-06 Sudeep Das , Amir Hajian , David N. Spergel