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One of the foundations of the Standard Model of Cosmology is statistical isotropy, which can be tested, among other probes, through the study of the Cosmic Microwave Background (CMB). However, a hemispherical power asymmetry on large scales…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-15 C. Gimeno-Amo , R. B. Barreiro , E. Martínez-González , A. Marcos-Caballero

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

We introduce a class of models in which statistical isotropy is broken spontaneously in the CMB by a non-linear response to long-wavelength fluctuations in a mediating field. These fluctuations appear as a gradient locally and pick out a…

Astrophysics · Physics 2008-11-26 Christopher Gordon , Wayne Hu , Dragan Huterer , Tom Crawford

A simple algorithm which gives the multipole vectors in terms of the roots of a polynomial is given. We find that the reported alignmet of the low l multipole vectors can be summarised as an anti-alignmet of these with the dipole direction.…

Astrophysics · Physics 2008-12-18 Robert C. Helling , Peter Schupp , Tiberiu Tesileanu

[Abridged] In this paper we explore a local non-linear perturbative model up to third order as a general characterization of the CMB anisotropies. We focus our analysis in large scale anisotropies. At these angular scales, the non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 P. Vielva , J. L. Sanz

We report here the first full sky component separation and CMB power spectrum estimation using a Wiener filtering technique on simulated data from the upcoming MAP experiment, set to launch in early 2001. The simulations included…

Astrophysics · Physics 2009-10-31 S. Prunet , R. Teyssier , S. T. Scully , F. R. Bouchet , R. Gispert

We measure the angular bispectrum of the cosmic microwave background (CMB) radiation anisotropy from the COBE Differential Microwave Radiometer (DMR) four-year sky maps. The angular bispectrum is the harmonic transform of the three-point…

Using the published WMAP 5-year data, we first show how sensitive the WMAP power spectra are to the form of the WMAP beam. It is well known that the beam profile derived from observations of Jupiter is non-Gaussian and indeed extends, in…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-01 U. Sawangwit , T. Shanks

The natural outcome of theoretical calculations of microwave background anisotropy is the angular power spectrum ${\cal C}_\ell$ as a function of multipole number $\ell$. Experimental ${\cal C}_\ell$'s are needed for direct comparison.…

Astrophysics · Physics 2009-09-25 J. Richard Bond

Since WMAP and Planck some anomalous features appeared in the Cosmic Microwave Background (CMB) large-angle anisotropy, the so-called anomalies. One of these is the hemispherical power asymmetry, i.e. a difference in the average power on…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-06 Giacomo Galloni , Nicola Bartolo , Sabino Matarrese , Marina Migliaccio , Angelo Ricciardone , Nicola Vittorio

We present two novel methods for the estimation of the angular power spectrum of cosmic microwave background (CMB) anisotropies. We assume an absolute CMB experiment with arbitrary asymmetric beams and arbitrary sky coverage. The methods…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Elina Keihänen , Kimmo Kiiveri , Hannu Kurki-Suonio , Martin Reinecke

The "dark flow" dipole is a statistically significant dipole found at the position of galaxy clusters in filtered maps of Cosmic Microwave Background (CMB) temperature anisotropies. The dipole measured in WMAP 3, 5 and 7 yr data releases…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-23 Fernando Atrio-Barandela , Alexander Kashlinsky , Harald Ebeling , Dale J. Fixsen , Dale Kocevski

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…

Astrophysics · Physics 2009-01-13 A. Bonaldi , S. Ricciardi , S. Leach , F. Stivoli , C. Baccigalupi , G. De Zotti

[Abridged] We apply the multipole vector framework to full-sky maps derived from the first year WMAP data. We significantly extend our earlier work showing that the two lowest cosmologically interesting multipoles, l=2 and 3, are not…

Astrophysics · Physics 2009-11-11 C. J. Copi , D. Huterer , D. J. Schwarz , G. D. Starkman

Abbreviated: We highlight the remarkable evolution in the CMB power spectrum over the past few years, and in the cosmological parameters for minimal inflation models derived from it. Grand unified spectra (GUS) show pre-WMAP optimal…

Astrophysics · Physics 2015-06-24 J. R. Bond , C. R. Contaldi , D. Pogosyan

Statistical isotropy is often assumed in cosmology and should be tested rigorously against observational data. We construct simple quadratic estimators to reconstruct asymmetry in the primordial power spectrum from CMB temperature and…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-16 Yin-Zhe Ma , George Efstathiou , Anthony Challinor

Recent claims in the literature have suggested that the {\it WMAP} quadrupole is not primordial in origin, and arises from an aliasing of the much larger dipole field because of incorrect satellite pointing. We attempt to reproduce this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Adam Moss , Douglas Scott , Kris Sigurdson

We confront predictions of inflationary scenarios with the WMAP data, in combination with complementary small-scale CMB measurements and large-scale structure data. The WMAP detection of a large-angle anti-correlation in the…

The CMB polarization is the Everest in the quest to characterize the earliest photons from the Universe. After a long list of ever-decreasing upper limits, a detection of polarization was made in 2002 by the DASI team at ell =~ 500. The…

Instrumentation and Methods for Astrophysics · Physics 2024-11-28 Denis Barkats

In cosmic microwave background (CMB) experiments, foreground-cleaned temperature maps are still contaminated by the residual dipole due to uncertainties of the Doppler dipole direction and microwave radiometer sidelobe. To obtain reliable…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-16 Hao Liu , Ti-Pei Li
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