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We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

We investigate some of the asymmetries reported in the CMB temperature angular distribution considering the {\Lambda}CDM model in the 3, 5 and 7 year WMAP data. We aim to analyze the 4 quadrants of the ILC CMB maps using 3 Galactic cuts:…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-03 Larissa Santos , Thyrso Villela , Carlos Alexandre Wuensche

Persistent evidence for a cosmic hemispherical asymmetry in the temperature field of cosmic microwave background (CMB) as observed by both WMAP as well as PLANCK increases the possibility of its cosmological origin. Presence of this signal…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-28 Suvodip Mukherjee , Pavan K. Aluri , Santanu Das , Shabbir Shaikh , Tarun Souradeep

We study the directional dependence of the angular two-point correlation function in maps of the cosmic microwave background (CMB). We propose two new statistics, one which measures the correlation of each point in the sky with a ring of…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-20 Sophie Zhang

Suggestions have been made that the microwave background observed by COBE and WMAP and dubbed Cosmic Microwave Background (CMB) may have an origin within our own Galaxy or Earth. To consider the signal that may be correlated with Earth, a…

Astrophysics · Physics 2007-05-23 Ria Follop , Anais Rassat , Asantha Cooray , Filipe B. Abdalla

We test the tenet of statistical isotropy of the standard cosmological model via a homology analysis of the cosmic microwave background temperature maps. Examining small sectors of the normalized maps, we find that the results exhibit a…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-21 Pratyush Pranav , Thomas Buchert

Cosmic Microwave Background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the northern and southern…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Marcio O'Dwyer , Craig J. Copi , Lloyd Knox , Glenn D. Starkman

Several claims have been made of anomalies in the large-angle properties of the cosmic microwave background anisotropy as measured by WMAP. In most cases, the statistical significance of these anomalies is hard or even impossible to assess,…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-11 Emory F. Bunn

We cross correlate the large-scale cosmic microwave background (CMB) sky measured by WMAP with two probes of large-scale structure at z ~ 1. The hard X-ray background, measured by the HEAO-1 satellite, is positively correlated with the WMAP…

Astrophysics · Physics 2008-11-26 Stephen Boughn , Robert Crittenden

We report the results of a statistical analysis performed with the four foreground-cleaned Planck maps by means of a suitably defined {\it local-variance} estimator. Our analysis shows a clear dipolar structure in Planck's {\it variance…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-17 A. Bernui , A. F. Oliveira , T. S. Pereira

We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Sabir Ramazanov , Grigory Rubtsov

In this paper, we explore the power of the cosmic microwave background (CMB) polarization (E-mode) data to corroborate four potential anomalies in CMB temperature data: the lack of large angular-scale correlations, the alignment of the…

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…

General Relativity and Quantum Cosmology · Physics 2021-05-28 Ivan Agullo , Dimitrios Kranas , V. Sreenath

Both the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck observations reported the hemispherical asymmetry of the cosmic microwave background (CMB) temperature fluctuation. The hemispherical asymmetry might be stemmed from the…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-13 Zhe Chang , Sai Wang

The Wilkinson Microwave Anisotropy Probe (WMAP) has measured lower amplitudes for the temperature quadrupole and octopole anisotropies than expected in the best fitting (concordance) Lambda-dominated cold dark matter cosmology. Some authors…

Astrophysics · Physics 2009-11-10 G. Efstathiou

Several anomalies appear to be present in the large-angle cosmic microwave background (CMB) anisotropy maps of WMAP, including the alignment of large-scale multipoles. Models in which isotropy is spontaneously broken (e.g., by a scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Haoxuan Zheng , Emory F. Bunn

We present results from a test for the Gaussianity of the whole sky sub-degree scale CMB temperature anisotropy measured by the Wilkinson Microwave Anisotropy Probe (WMAP). We calculate the genus from the foreground-subtracted and…

Astrophysics · Physics 2010-04-06 Chan-Gyung Park

To reliably detect the cosmic microwave background (CMB) anisotropy is of great importance in understanding the birth and evolution of the Universe. One of the difficulties in CMB experiments is the domination of measured CMB anisotropy…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-28 Hao Liu , Ti-Pei Li

The recent WMAP data represents a milestone in cosmology and helps constrain cosmological parameters with unprecedented accuracy. In this work we combine the WMAP data with previous CMB anisotropy measurements at smaller angular scales to…

Astrophysics · Physics 2015-06-24 C. J. Odman

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…

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