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Anomalies in the cosmic microwave background (CMB) refer to features that have been observed, mostly at large angular scales, and which show some tension with the statistical predictions of the standard $\Lambda$CDM model. In this work, we…

广义相对论与量子宇宙学 · 物理学 2021-05-28 Ivan Agullo , Dimitrios Kranas , V. Sreenath

We describe our methodology for comparing the WMAP measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data, and the tight constraints on…

y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas…

宇宙学与河外天体物理 · 物理学 2013-03-13 Rashid A. Sunyaev , Rishi Khatri

Given an arbitrary function, we may construct symmetric and antisymmetric functions under a certain operation. Since statistical isotropy and homogeneity of our Universe has been a fundamental assumption of modern cosmology, we do not…

宇宙学与河外天体物理 · 物理学 2012-08-23 Jaiseung Kim , Pavel Naselsky , Martin Hansen

The statistical expectation values of the temperature fluctuations and polarization of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We investigate the statistical isotropy (SI) of the CMB maps…

天体物理学 · 物理学 2009-11-11 Tarun Souradeep , Amir Hajian , Soumen Basak

If the principle of statistical isotropy is valid, then the angular power spectrum (APS) of cosmic microwave background (CMB) radiation is uncorrelated between different multipoles. We propose a novel technique to analyse any possible…

宇宙学与河外天体物理 · 物理学 2022-12-29 Md Ishaque Khan , Rajib Saha

The origin of small deviations from statistical isotropy in the Cosmic Microwave Background (CMB) - the so-called CMB anomalies - remains an open question in modern cosmology. In this work, we test statistical isotropy in Planck Data…

宇宙学与河外天体物理 · 物理学 2025-04-09 C. Gimeno-Amo , F. K. Hansen , E. Martínez-González , R. B. Barreiro , A. J. Banday

We investigate a possible asymmetry in the statistical properties of the cosmic microwave background temperature field and to do so we construct an estimator aiming at detecting a dipolar modulation. Such a modulation is found to induce…

天体物理学 · 物理学 2009-11-10 Simon Prunet , Jean-Philippe Uzan , Francis Bernardeau , Tristan Brunier

Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a linearized formula for relating them to the temperature blackbody fluctuations. However, this procedure also…

宇宙学与河外天体物理 · 物理学 2016-08-17 Alessio Notari , Miguel Quartin

Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a \emph{linearized} formula for relating them to the temperature blackbody fluctuations. However such a procedure…

宇宙学与河外天体物理 · 物理学 2016-08-24 Alessio Notari , Miguel Quartin

We estimate Cosmic Microwave Background (CMB) polarisation power spectra, and temperature-polarisation cross-spectra, from the 9-year data of the Wilkinson Microwave Anisotropy Probe (WMAP). Foreground cleaning is implemented using minimum…

宇宙学与河外天体物理 · 物理学 2016-03-02 Soumen Basak , Jacques Delabrouille

We investigate the anisotropy in cosmic microwave background Planck maps due to the coupling between its beam asymmetry and uneven scanning strategy. Introducing a pixel space estimator based on the temperature gradients, we find a highly…

宇宙学与河外天体物理 · 物理学 2014-07-17 Ben Rathaus , Ely D. Kovetz

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

Recent observations suggest that there are violations of the isotropy of the universe at large scales, an important part of the cosmological principle. In this paper, we use the Cosmic Microwave Background (CMB) data to search for spatial…

宇宙学与河外天体物理 · 物理学 2022-04-20 Shek Yeung , Ming-Chung Chu

Cosmic microwave background (CMB) radiation data obtained by different experiments contain, besides the desired signal, a superposition of microwave sky contributions. We present a fast and robust method, using a wavelet decomposition on…

宇宙学与河外天体物理 · 物理学 2013-05-24 R. Fernández-Cobos , P. Vielva , R. B. Barreiro , E. Martínez-González

The report of a significant deviation of the CMB temperature anisotropies distribution from Gaussianity (soon after the public release of the WMAP data in 2003) has become one of the most solid WMAP anomalies. This detection grounds on an…

宇宙学与河外天体物理 · 物理学 2015-05-19 P. Vielva

We review aspects of Cosmic Microwave Background (CMB) spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by…

宇宙学与河外天体物理 · 物理学 2016-04-13 G. De Zotti , M. Negrello , G. Castex , A. Lapi , M. Bonato

A search for matched circle pairs of similar temperature fluctuations in the final WMAP 9yr data is carried out. Such a signature is expected if the space of the Universe is multiply connected. We investigate the relation between the pixel…

宇宙学与河外天体物理 · 物理学 2013-10-22 Ralf Aurich , Sven Lustig

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…

天体物理学 · 物理学 2009-01-13 A. Bonaldi , S. Ricciardi , S. Leach , F. Stivoli , C. Baccigalupi , G. De Zotti

We study the spectral and morphological characteristics of the diffuse Galactic emission in the WMAP temperature data using a template-based multi-linear regression, and obtain the following results. 1. We confirm previous observations of a…

天体物理学 · 物理学 2009-06-23 Gregory Dobler , Douglas P. Finkbeiner