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Related papers: Features in the primordial power spectrum? A frequ…

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We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are…

We reconstruct the shape of the primordial power spectrum of curvature perturbations in extended cosmological models, including addition of massive neutrinos, extra relativistic species or varying primordial helium abundance, from the…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-18 Zong-Kuan Guo , Yuan-Zhong Zhang

The latest cosmological data seem to indicate a significant deviation from scale invariance of the primordial power spectrum when parameterized either by a power law or by a spectral index with non-zero "running". This deviation, by itself,…

Astrophysics · Physics 2011-05-12 Licia Verde , Hiranya V. Peiris

We use the localized principle component analysis to detect deviations from scale invariance of the primordial power spectrum of curvature perturbations. With the technique we make uncorrelated estimates of the primordial power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-25 Zong-Kuan Guo , Yuan-Zhong Zhang

We reconstruct the primordial spectrum of the curvature perturbation, $P(k)$, from the observational data of the Wilkinson Microwave Anisotropy Probe (WMAP) by the cosmic inversion method developed recently. In contrast to conventional…

Astrophysics · Physics 2009-10-09 Noriyuki Kogo , Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama

CMB photons travel from the last scattering surface, when the primary CMB has been generated, along the surface of the light cone to us. During their travel, they are affected by many secondary effects such as the integrated Sachs-Wolfe…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-11 Mario Ballardini

The basic cosmological parameters and the primordial power spectrum together completely specify predictions for the cosmic microwave background radiation anisotropy and large scale structure. Here we show how we can strongly constrain both…

Astrophysics · Physics 2010-11-30 Yun Wang , David N. Spergel , Michael A. Strauss

The recent Planck data on the power spectrum of temperature anisotropies of the cosmic microwave background marginally support deviations from the $\Lambda$CDM model at several multipoles. With a view towards current and forthcoming…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Spyros Sypsas

We study features in the bispectrum of the primordial curvature perturbation correlated with the reconstructed primordial power spectrum from the observed cosmic microwave background temperature data. We first show how the bispectrum can be…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-25 Stephen Appleby , Jinn-Ouk Gong , Dhiraj Kumar Hazra , Arman Shafieloo , Spyros Sypsas

A model-independent determination of the primordial power spectrum of matter density fluctuations could uniquely probe physics of the very early universe, and provide powerful constraints on inflationary models. We parametrize the…

Astrophysics · Physics 2009-10-31 Yun Wang , Grant J. Mathews

We allow a more general (step-function) form of the primordial power spectrum than the usual featureless power-law Harrison--Zeldovich (with spectral index n=1) power spectrum, and fit it to the latest Cosmic Microwave Background data sets.…

Astrophysics · Physics 2009-11-07 O. Elgaroy , M. Gramann , O. Lahav

We propose and develop a formalism to describe and constrain statistically anisotropic primordial perturbations. Starting from a decomposition of the primordial power spectrum in spherical harmonics, we find how the temperature fluctuations…

Astrophysics · Physics 2009-11-13 C. Armendariz-Picon

In this work we explore the possibility of variations in the primordial scalar power spectrum around the power-law shape, as predicted by single-field slow-roll inflationary scenarios. We search for the trace of these fluctuations in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Marzieh Farhang , Muhammad Sadegh Esmaeilian

We analyze the three-year WMAP temperature anisotropy data seeking to confirm the power spectrum and likelihoods published by the WMAP team. We apply five independent implementations of four algorithms to the power spectrum estimation and…

Current measurements of the temperature and polarization anisotropy power spectra of the Cosmic Microwave Background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Victor Miralles , Héctor Ramírez , Lotfi Boubekeur

Angular power spectrum of the cosmic microwave background (CMB) temperature anisotropies is one of the most important on characteristics of the Universe such as its geometry and total density. Using flat sky approximation and Fourier…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Lung-Yih Chiang , Fei-Fan Chen

Measuring the primordial matter power spectrum is our primary means of probing unknown physics in the very early universe. We allow the primordial power spectrum to be an arbitrary function, and parametrize it in terms of wavelet band…

Astrophysics · Physics 2009-11-07 Pia Mukherjee , Yun Wang

The form of the primordial power spectrum has the potential to differentiate strongly between competing models of perturbation generation in the early universe and so is of considerable importance. The recent release of five years of WMAP…

Astrophysics · Physics 2015-05-13 M. Bridges , F. Feroz , M. P. Hobson , A. N. Lasenby

The new three year WMAP data seem to confirm the presence of non-standard large scale features in the Cosmic Microwave Anisotropies power spectrum. While these features may hint at uncorrected experimental systematics, it is also possible…

Astrophysics · Physics 2009-11-11 Laura Covi , Jan Hamann , Alessandro Melchiorri , Anze Slosar , Irene Sorbera

In inflationary models with minimal amount of gravity waves, the primordial power spectrum of density fluctuations, $A_S^2(k)$, together with the basic cosmological parameters, completely specify the predictions for the cosmic microwave…

Astrophysics · Physics 2009-10-31 Yun Wang , David N. Spergel , Michael A. Strauss