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We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2007-05-23 Tomo Takahashi

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…

Astrophysics · Physics 2009-11-11 Tarun Souradeep , Amir Hajian , Soumen Basak

Recent Wilkinson Microwave Anisotropy Probe (WMAP) data confirm the Cosmic Microwave Background (CMB) quadrupole anomaly. We further elaborate our previous proposal that the quadrupole power can be naturally suppressed in axis-symmetric…

Astrophysics · Physics 2008-11-26 L. Campanelli , P. Cea , L. Tedesco

The low quadrupole of the cosmic microwave background (CMB), measured by COBE and confirmed by WMAP, has generated much discussion recently. We point out that the well-known correlation between temperature and polarization anisotropies of…

Astrophysics · Physics 2009-06-15 Olivier Doré , Gilbert P. Holder , Abraham Loeb

Anisotropies in distortions to the frequency spectrum of the cosmic microwave background (CMB) can be created through spatially varying heating processes in the early Universe. For instance, the dissipation of small-scale acoustic modes…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Jens Chluba , Emanuela Dimastrogiovanni , Mustafa A. Amin , Marc Kamionkowski

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2009-11-06 Masahiro Kawasaki , Takeo Moroi , Tomo Takahashi

Measurements of the cosmic microwave background (CMB) spectral $y$-distortion anisotropy offer a test for the statistical isotropy of the primordial density perturbations on $0.01\lesssim k{\rm Mpc}\lesssim 1$. We compute the 1-point…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-28 Atsuhisa Ota

We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum, which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field. We find new configurations in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-03 Maresuke Shiraishi , Shuichiro Yokoyama

Several anomalies appear to be present in the large-angle cosmic microwave background (CMB) anisotropy maps of WMAP. One of these is a lack of large-scale power. Because the data otherwise match standard models extremely well, it is natural…

Astrophysics · Physics 2008-12-18 Emory F. Bunn , Austin Bourdon

The divergence of the momentum density field of the large scale structure generates a secondary anisotropy contribution to the Cosmic Microwave Background (CMB). While the effect is best described as a non-linear extension to the well-known…

Astrophysics · Physics 2009-11-13 Asantha Cooray , Naoki Seto

All the analyses of Cosmic Microwave Background (CMB) temperature maps up--to--date show that CMB anisotropies follow a Gaussian distribution. On the other hand, astrophysical foregrounds which hamper the detection of the CMB angular power…

Astrophysics · Physics 2008-11-26 F. Argüeso , J. González-Nuevo , L. Toffolatti

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

Analyses of recent cosmic microwave background (CMB) observations have provided increasing indications for the existence of large scale anisotropy in the universe. Given the far reaching consequences of such an anisotropy for our…

Astrophysics · Physics 2009-09-29 A. Bernui , B. Mota , M. J. Reboucas , R. Tavakol

The statistical expectation values of the temperature fluctuations of the Cosmic Microwave Background (CMB) are assumed to be preserved under rotations of the sky. We investigate the Statistical Isotropy (SI) of the CMB anisotropy maps…

Astrophysics · Physics 2009-11-10 Amir Hajian , Tarun Souradeep , Neil Cornish

Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 Md Ishaque Khan , Rajib Saha

We discuss the non-Gaussian contribution to the power spectrum covariance of cosmic microwave background (CMB) anisotropies resulting through weak gravitational lensing angular deflections and the correlation of deflections with secondary…

Astrophysics · Physics 2009-11-07 Asantha Cooray

We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear $\delta…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Hooshyar Assadullahi , Hassan Firouzjahi , Mohammad Hossein Namjoo , David Wands

We investigate the statistical anisotropy and Gaussianity of temperature fluctuations of Cosmic Microwave Background radiation (CMB) data from {\it Wilkinson Microwave Anisotropy Probe} survey, using the multifractal detrended fluctuation…

Astrophysics · Physics 2011-08-04 M. Sadegh Movahed , F. Ghasemi , Sohrab Rahvar , M. Reza Rahimi Tabar

Sky temperature map of the cosmic microwave background (CMB) is one of the premier probes of cosmology. To minimize instrumentally induced systematic errors, CMB anisotropy experiments measure temperature differences across the sky using…

Astrophysics · Physics 2008-06-30 Hao Liu , Ti-Pei Li

Non-linear evolution of cosmological energy density fluctuations triggers deviations from Gaussianity in the temperature distribution of the cosmic microwave background. A method to estimate these deviations is proposed. N-body simulations…

Astrophysics · Physics 2009-11-07 A. M. Aliaga , V. Quilis , J. V. Arnau , D. Saez