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Fluctuations in the temperature of the cosmic microwave background have now been detected over a wide range of angular scales, and a consistent picture seems to be emerging. This article describes some of the implications for cosmology.…

Astrophysics · Physics 2009-10-28 Douglas Scott , Joe Silk , Martin White

Full-sky maps of the cosmic microwave background temperature reveal a 7% asymmetry of fluctuation power between two halves of the sky. A common phenomenological model for this asymmetry is an overall dipole modulation of statistically…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Simone Aiola , Bingjie Wang , Arthur Kosowsky , Tina Kahniashvili , Hassan Firouzjahi

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…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-22 Ralf Aurich , Sven Lustig

The large-angle (low-l) correlations of the Cosmic Microwave Background exhibit several statistically significant anomalies compared to the standard inflationary big-bang model, however no connection has hitherto been drawn between them.…

Astrophysics · Physics 2009-11-10 Dominik J. Schwarz , Glenn D. Starkman , Dragan Huterer , Craig J. Copi

We explore the low-l likelihood of the angular spectrum C(l) of masked CMB temperature maps using an adaptive importance sampler. We find that, in spite of a partial sky coverage, the likelihood distribution of each C(l) closely follows an…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 K. Benabed , J. -F. Cardoso , S. Prunet , E. Hivon

We revisit the alignments of the largest structures observed in the cosmic microwave background (CMB) using the seven and nine-year WMAP and first-year Planck data releases. The observed alignments -- the quadrupole with the octopole and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

The recent release of the first light sky map of the cosmic microwave background (CMB) from the Planck satellite provides an initial opportunity for comparison with the WMAP and COBE sky maps and their reconstruction algorithms. The…

General Physics · Physics 2010-11-15 Keith S. Cover

This article investigates the signature of the seventeen multi-connected flat spaces in cosmic microwave background (CMB) maps. For each such space it recalls a fundamental domain and a set of generating matrices, and then goes on to find…

The amplitudes of the quadrupole and octopole measured from the Wilkinson Microwave Anisotropy Probe (WMAP) appear to be lower than expected according to the concordance Lambda CDM cosmology. However, the pseudo-Cl estimator used by the…

Astrophysics · Physics 2009-07-09 G. Efstathiou

Recently a symmetry-based method to test for statistical isotropy of the cosmic microwave background was developed. We apply the method to template-cleaned 3-year and 5-year WMAP-$DA$ maps. We examine a wide range of angular multipoles from…

Astrophysics · Physics 2010-11-02 Pramoda Kumar Samal , Rajib Saha , Pankaj Jain , John P. Ralston

We investigate the abundance of large-scale hot and cold spots in the WMAP-5 temperature maps and find considerable discrepancies compared to Gaussian simulations based on the LCDM best-fit model. Too few spots are present in the reliably…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Youness Ayaita , Maik Weber , Christof Wetterich

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…

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

There have recently been several claims of an asymmetric distribution of large scale fluctuations in the WMAP data. I review some recent results from a test of isotropy of the power spectrum at all scales and show how the power is…

Astrophysics · Physics 2007-05-23 F. K. Hansen

At the largest angular scales the presence of a number of unexpected features has been confirmed by the latest measurements of the cosmic microwave background (CMB). Among them are the anomalous alignment of the quadrupole and octopole with…

Astrophysics · Physics 2008-11-26 Aleksandar Rakic , Dominik J. Schwarz

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

We point out that the recent WMAP findings of a suppressed large scale power in the Cosmic Microwave Background anisotropy power spectrum, if of cosmological origin, make the case for a new cosmic coincidence problem.The observed…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alessandro Melchiorri , Laura Mersini-Houghton

We discuss how an extended foreground of the cosmic microwave background (CMB) can account for the anomalies in the low multipoles of the CMB anisotropies. The distortion needed to account for the anomalies is consistent with a cold spot…

Astrophysics · Physics 2009-11-11 L. Raul Abramo , Laerte Sodre , Carlos Alexandre Wuensche

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

WMAP observations have accurately determined the position of the first two peaks and dips in the CMB temperature power spectrum. These encode information on the ratio of the distance to the last scattering surface to the sound horizon at…

Astrophysics · Physics 2008-11-26 Pier Stefano Corasaniti , Alessandro Melchiorri