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We estimate CMB polarization and temperature power spectra using WMAP 5-year foreground contaminated maps. The power spectrum is estimated by using a model independent method, which does not utilize directly the diffuse foreground templates…

宇宙学与河外天体物理 · 物理学 2011-02-11 Pramoda Kumar Samal , Rajib Saha , Jacques Delabrouille , Simon Prunet , Pankaj Jain , Tarun Souradeep

Precise measurements of the anisotropies in the cosmic microwave background enable us to do an accurate study on the form of the primordial power spectrum for a given set of cosmological parameters. In a previous paper (Shafieloo and…

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…

天体物理学 · 物理学 2009-03-18 Lung-Yih Chiang , Pavel D. Naselsky , Peter Coles

Recently, two issues concerning the three-year WMAP likelihood code were pointed out. On large angular scales ($l \lesssim 30$), a sub-optimal likelihood approximation resulted in a small power excess. On small angular scales ($l \gtrsim…

天体物理学 · 物理学 2007-05-23 Jostein R. Kristiansen , Hans Kristian Eriksen , Oystein Elgaroy

Obscuration due to Galactic emission complicates the extraction of information from cosmological surveys, and requires some combination of the (typically imperfect) modeling and subtraction of foregrounds, or the removal of part of the sky.…

宇宙学与河外天体物理 · 物理学 2011-11-14 Stephen M. Feeney , Hiranya V. Peiris , Andrew Pontzen

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…

天体物理学 · 物理学 2009-11-13 Rajib Saha , Pankaj Jain , Tarun Souradeep

Suppression in primordial power on the Universe's largest observable scales has been invoked as a possible explanation for large-angle observations in the cosmic microwave background, and is allowed or predicted by some inflationary models.…

宇宙学与河外天体物理 · 物理学 2011-04-04 Cameron Gibelyou , Dragan Huterer , Wenjuan Fang

We present circular and linear cross-correlation tests and the "friend-of-friend" analysis for phases of the Internal Linear Combination Map (ILC) and the WMAP foregrounds for all K--W frequency bands at the range of multipoles…

天体物理学 · 物理学 2009-11-10 P. D. Naselsky , A. G. Doroshkevich , O. V. Verkhodanov

The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has…

天体物理学 · 物理学 2011-04-11 Tarun Souradeep , Rajib Saha , Pankaj Jain

We use recent results from the Wilkinson Microwave Anisotropy Probe (WMAP) for the locations of peaks and troughs of the Cosmic Microwave Background (CMB) power spectrum, together with constraints from large-scale structure, to study a…

天体物理学 · 物理学 2009-11-07 T. Barreiro , M. C. Bento , N. M. C. Santos , A. A. Sen

In cosmic microwave background (CMB) experiments, foreground-cleaned temperature maps are still contaminated by the residual dipole due to uncertainties of the Doppler dipole direction and microwave radiometer sidelobe. To obtain reliable…

宇宙学与河外天体物理 · 物理学 2013-01-16 Hao Liu , Ti-Pei Li

The possibility that the cosmic variance outliers present in the recently released WMAP multipole moments are due to oscillations in the primordial power spectrum is investigated. Since the most important contribution to the WMAP likelihood…

天体物理学 · 物理学 2008-11-26 Jerome Martin , Christophe Ringeval

The Cosmic Microwave Background (CMB) reaches homogeneity at relatively modest angular scales compared to the expectation of the standard $\Lambda$CDM model revealing an important challenge to the theoretical predictions. We analyze this…

We measure the angular power spectrum of the WMAP first-year temperature anisotropy maps. We use SpICE (Spatially Inhomogeneous Correlation Estimator) to estimate Cl's for multipoles l=2-900 from all possible cross-correlation channels.…

天体物理学 · 物理学 2009-11-10 Pablo Fosalba , Istvan Szapudi

We present a CMB temperature power spectrum measurement at large angular scales from WMAP and Planck maps that were cleaned of foregrounds using a template-based approach described in a companion paper. We recover essentially the full-sky…

宇宙学与河外天体物理 · 物理学 2025-09-05 Hayley C. Nofi , Graeme E. Addison , Charles L. Bennett , Laura Herold , J. L. Weiland

We apply a previously developed Gibbs sampling framework to the foreground corrected 3-yr WMAP polarization data and compute the power spectrum and residual foreground template amplitude posterior distributions. We first analyze the…

天体物理学 · 物理学 2010-11-11 H. K. Eriksen , Greg Huey , A. J. Banday , K. M. Gorski , J. B. Jewell , I. J. O'Dwyer , B. D. Wandelt

We analyse the low--multipole components of the weak-lensing convergence field in a FLRW universe. The low--multipole convergence field, encodes the largest-angle coherent potential gradients, essential for assessment of large-angle…

宇宙学与河外天体物理 · 物理学 2026-04-28 Albert Bonnefous , Roya Mohayaee

A previous work (Monteser\'in et al. 2008) estimated the CMB variance from the three-year WMAP data, finding a lower value than expected from Gaussian simulations using the WMAP best-fit cosmological model. We repeat the analysis on the…

宇宙学与河外天体物理 · 物理学 2015-05-18 M. Cruz , P. Vielva , E. Martínez-González , R. B. Barreiro

The observed angular power spectrum of the cosmic microwave background temperature anisotropy, $C_l$, is a convolution of a cosmological radiative transport kernel with an assumed primordial power spectrum of inhomogeneities. Exquisite…

天体物理学 · 物理学 2009-11-10 Arman Shafieloo , Tarun Souradeep

Several analyses of the microwave sky maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have drawn attention to alignments amongst the low-order multipoles. Amongst the various possible explanations, an effect of cosmic topology has…

天体物理学 · 物理学 2009-11-13 James G. Cresswell , Andrew R. Liddle , Pia Mukherjee , Alain Riazuelo