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Related papers: Superimposed Oscillations in the WMAP Data?

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Large-scale modes in the temperature anisotropy power spectrum C_l measured by the Wilkinson Microwave Anisotropy Probe (WMAP), seem to have lower amplitudes (C_2, C_3 and C_4) than that expected in the so called concordance LCDM model. In…

Astrophysics · Physics 2009-11-07 E. Gaztanaga , J. Wagg , T. Multamaki , A. Montana , D. H. Hughes

A novel primordial spectrum with a dynamical scale of quantum gravity origin is proposed to explain the sharp fall off of the angular power spectra at low multipoles in the COBE and WMAP observations. The spectrum is derived from quantum…

Astrophysics · Physics 2009-11-10 Ken-ji Hamada , Tetsuyuki Yukawa

A primordial magnetic field in the early universe will cause Faraday rotation of the linear polarization of the cosmic microwave background generated via Compton scattering at the surface of last scattering. This rotation induces a non-zero…

Astrophysics · Physics 2009-08-11 Tina Kahniashvili , Yurii Maravin , Arthur Kosowsky

We perform a likelihood analysis of the recently released BOOMERanG and MAXIMA data, allowing for the possibility of a time-varying fine-structure constant. We find that in general this data prefers a value of $\alpha$ that was smaller in…

Astrophysics · Physics 2008-11-26 P. P. Avelino , C. J. A. P. Martins , G. Rocha , P. Viana

Many recent analyses have indicated that large scale WMAP data display anomalies that appear inconsistent with the standard cosmological paradigm. However, the effects of foreground contamination, which require elimination of some fraction…

Astrophysics · Physics 2009-11-10 Anze Slosar , Uros Seljak

We argue that the observed large-scale cosmic microwave anomalies, discovered by WMAP and confirmed by the Planck satellite, are most naturally explained in the context of a marginally-open universe. Particular focus is placed on the dipole…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 Andrew R Liddle , Marina Cortês

We consider a class of inflationary models with small oscillations imprinted on an otherwise smooth inflaton potential. These oscillations are manifest as oscillations in the power spectrum of primordial perturbations, which then give rise…

Astrophysics · Physics 2009-11-13 Cédric Pahud , Marc Kamionkowski , Andrew R Liddle

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-09 C. Gimeno-Amo , F. K. Hansen , E. Martínez-González , R. B. Barreiro , A. J. Banday

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

A linear modulation of the primordial perturbations is proposed as an explanation for the observed asymmetry between the northern and southern hemispheres of the Wilkinson Microwave Anisotropy Probe (WMAP) data. A cut sky, reduced…

Astrophysics · Physics 2008-11-26 Christopher Gordon

We use the 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…

Astrophysics · Physics 2016-11-09 T. Barreiro , M. C. Bento , N. M . C. Santos , A. A. Sen

The WMAP and Planck observations show that the quadrupole and octopole orientations of the CMB might align with each other. We reveal that the quadrupole--octopole alignment is a natural implication of the primordial power spectrum in an…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-12 Zhe Chang , Xin Li , Sai Wang

We discuss the role of gravitational excitons/radions in different cosmological scenarios. Gravitational excitons are massive moduli fields which describe conformal excitations of the internal spaces and which, due to their Planck-scale…

Astrophysics · Physics 2007-05-23 Uwe Guenther , Alexander Zhuk

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…

Astrophysics · Physics 2009-11-07 T. Barreiro , M. C. Bento , N. M. C. Santos , A. A. Sen

The Doppler dipole signal dominates the cosmic microwave background (CMB) anisotropy maps obtained by the Wilkinson Microwave Anisotropy Probe (WMAP) mission, and plays a key role throughout the data processing. Previously, we discovered a…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-03 Hao Liu , Shao-Lin Xiong , Ti-Pei Li

We investigate the large scale anomalies in the angular distribution of the cosmic microwave background radiation as measured by WMAP using several tests. These tests, based on the multipole vector expansion, measure correlations between…

The dipolar model \cite{Gordon:2005ai} has attracted much interest because it may phenomenologically explain the CMB hemispherical power asymmetry found in the WMAP and Planck data. Since such a model explicitly breaks isotropy at large…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-24 L. Polastri , A. Gruppuso , P. Natoli

The latest analysis of the cosmic microwave background by the Planck team finds more smoothing of the acoustic peaks in the temperature power spectrum than predicted by $\Lambda$CDM. Here we investigate whether this additional smoothing can…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-18 Guillem Domènech , Marc Kamionkowski

We study the power asymmetry between even and odd multipoles in the multipolar expansion of CMB temperature data from WMAP, recently reported in the literature. We introduce an alternate statistic which probes this effect more sensitively.…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-04 Pavan K. Aluri , Pankaj Jain

The WMAP determination of the baryon-to-photon ratio implies, through Big Bang nucleosynthesis, a cosmological Li abundance larger, by a factor of 2 to 3, than the Li abundance plateau observed in the oldest Pop II stars. It is however…

Astrophysics · Physics 2009-11-10 Olivier Richard , Georges Michaud , Jacques Richer