scholarly journals Doppler Peaks in the Angular Power Spectrum of the Cosmic Microwave Background: A Fingerprint of Topological Defects

1996 ◽  
Vol 76 (4) ◽  
pp. 579-582 ◽  
Author(s):  
Ruth Durrer ◽  
Alejandro Gangui ◽  
Mairi Sakellariadou
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Topological Defects ◽  
Microwave Background ◽  
Angular Power Spectrum

A Measurement by BOOMERANG of Multiple Peaks in the Angular Power Spectrum of the Cosmic Microwave Background

2002 ◽  
Vol 571 (2) ◽  
pp. 604-614 ◽  
Author(s):  
C. B. Netterfield ◽  
P. A. R. Ade ◽  
J. J. Bock ◽  
J. R. Bond ◽  
J. Borrill ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Microwave Background ◽  
Angular Power Spectrum ◽  
Multiple Peaks

A Measurement of the Angular Power Spectrum of the Cosmic Microwave Background from [CLC][ITAL]l[/ITAL][/CLC] = 100 to 400

1999 ◽  
Vol 524 (1) ◽  
pp. L1-L4 ◽  
Author(s):  
A. D. Miller ◽  
R. Caldwell ◽  
M. J. Devlin ◽  
W. B. Dorwart ◽  
T. Herbig ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Microwave Background ◽  
Angular Power Spectrum

scholarly journals The polarimetric multi-frequency radio sources properties

2016 ◽  
Vol 25 (11) ◽  
pp. 1640005 ◽  
Author(s):  
Vincenzo Galluzzi ◽  
Marcella Massardi
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
State Of The Art ◽  
The State ◽  
Radio Sources ◽  
Microwave Background ◽  
Complete Sample ◽  
Angular Power Spectrum ◽  
Extragalactic Radio Sources ◽  
Compact Array

The polarization properties of extragalactic radio sources at frequencies higher than [Formula: see text]GHz are still poorly constrained. However, their characterization would provide invaluable information about the physics of the emission processes and is crucial to estimate their contamination as foregrounds of the polarized Cosmic Microwave Background (CMB) angular power spectrum on scales [Formula: see text]arcmin. In this contribution, after summarizing the state-of-the-art of polarimetric observations in the millimetric wavelength bands, we present our observations of a complete sample of 53 sources with [Formula: see text]mJy carried out with the Australia Telescope Compact Array (ACTA) between [Formula: see text] and [Formula: see text]GHz. The analysis clearly shows that polarization properties cannot be simply inferred from total intensity ones, as the spectral behaviors of the two signals are typically different.

scholarly journals Cosmic Strings and Their Induced Non-Gaussianities in the Cosmic Microwave Background

2010 ◽  
Vol 2010 ◽  
pp. 1-28 ◽  
Author(s):  
Christophe Ringeval
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Early Universe ◽  
Cosmic Strings ◽  
Point Function ◽  
Microwave Background ◽  
Angular Power Spectrum ◽  
Gravitational Perturbations ◽  
The One ◽  
Non Gaussian

Motivated by the fact that cosmological perturbations of inflationary quantum origin were born Gaussian, the search for non-Gaussianities in the cosmic microwave background (CMB) anisotropies is considered as the privileged probe of nonlinear physics in the early universe. Cosmic strings are active sources of gravitational perturbations and incessantly produce non-Gaussian distortions in the CMB. Even if, on the currently observed angular scales, they can only contribute a small fraction of the CMB angular power spectrum, cosmic strings could actually be the main source of its non-Gaussianities. In this paper, after having reviewed the basic cosmological properties of a string network, we present the signatures Nambu-Goto cosmic strings would induce in various observables ranging from the one-point function of the temperature anisotropies to the bispectrum and trispectrum. It is shown that string imprints are significantly different than those expected from the primordial type of non-Gaussianity and could therefore be easily distinguished.

scholarly journals A SEMI-ANALYTICAL APPROACH TO PERTURBATIONS IN MUTATED HILLTOP INFLATION

2012 ◽  
Vol 21 (02) ◽  
pp. 1250017 ◽  
Author(s):  
BARUN KUMAR PAL ◽  
SUPRATIK PAL ◽  
B. BASU
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Numerical Computation ◽  
Analytical Approach ◽  
Cosmological Perturbations ◽  
Microwave Background ◽  
Analytical Treatment ◽  
Angular Power Spectrum

We study cosmological perturbations and observational aspects for mutated hilltop model of inflation. Employing mostly analytical treatment, we evaluate observable parameters during inflation as well as post-inflationary perturbations. This further leads to exploring observational aspects related to cosmic microwave background (CMB) radiation. This semi-analytical treatment reduces complications related to numerical computation to some extent for studying the different phenomena related to CMB angular power spectrum for mutated hilltop inflation.

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