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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 observationally examine cosmological models based on primordial power spectra with quantized wavevectors. Introducing a linearly quantized power spectrum with $k_0=3.225\times10^{-4}\mathrm{Mpc}^{-1}$ and spacing $\Delta k = 2.257 \times…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 D. J. Bartlett , W. J. Handley , A. N. Lasenby

We reconstruct the power spectrum of primordial curvature perturbations by applying a well-validated non-parametric technique employing Tikhonov regularisation to the first data release from the Planck satellite. To improve the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-31 Paul Hunt , Subir Sarkar

We investigate a non-parametric Bayesian method for reconstructing the primordial power spectrum (PPS) of scalar perturbations using temperature and polarisation data from the {\em Planck}, ACT, and SPT CMB experiments. This reconstruction…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-30 Antonio Raffaelli , Mario Ballardini

Several satellite missions have uncovered a series of potential anomalies in the fluctuation spectrum of the cosmic microwave background temperature, including: (1) an unexpectedly low level of correlation at large angles, manifested via…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-04 Fulvio Melia , Qingbo Ma , Jun-Jie Wei , Bo Yu

Using modified Richardson-Lucy algorithm we reconstruct the primordial power spectrum (PPS) from Planck Cosmic Microwave Background (CMB) temperature anisotropy data. In our analysis we use different combinations of angular power spectra…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-19 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

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 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

We reconstruct the shape of the primordial power spectrum from the latest cosmic microwave background data, including the new results from the Wilkinson Microwave Anisotropy Probe (WMAP), and large scale structure data from the two degree…

Astrophysics · Physics 2009-11-07 S. L. Bridle , A. M. Lewis , J. Weller , G. Efstathiou

We present a minimally-parametric reconstruction of the primordial power spectrum using the most recent cosmic microwave background and large scale structure data sets. Our goal is to constrain the shape of the power spectrum while…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Hiranya V. Peiris , Licia Verde

The primordial power spectrum describes the initial perturbations that seeded the large-scale structure we observe today. It provides an indirect probe of inflation or other structure-formation mechanisms. In this letter, we recover the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-05 F. Lanusse , P. Paykari , J. -L. Starck , F. Sureau , J. Bobin , A. Rassat

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

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

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Stefano Gariazzo

We consider Cosmic Microwave Background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-10 William H. Kinney , Azadeh Moradinezhad Dizgah , Antonio Riotto

We develop an accurate and efficient Bayesian method to reconstruct the primordial power spectrum in a model-independent way, and apply it to the latest cosmic microwave background measurement from Planck mission, and the large scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-28 Xin Wang , Gong-Bo Zhao

The {\em Planck} DR3 measurements of the temperature and polarization anisotropies power spectra of the cosmic microwave background (CMB) show an excess of smoothing of the acoustic peaks with respect to $\Lambda$CDM, often quantified by a…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Mario Ballardini , Fabio Finelli

An inflationary gravitational wave background consistent with BICEP2 is difficult to reconcile with a simple power-law spectrum of primordial scalar perturbations. Tensor modes contribute to the temperature anisotropies at multipoles with…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-28 Kevork N. Abazajian , Grigor Aslanyan , Richard Easther , Layne C. Price

We present a minimally parametric, model independent reconstruction of the shape of the primordial power spectrum. Our smoothing spline technique is well-suited to search for smooth features such as deviations from scale invariance, and…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Andrea Ravenni , Licia Verde , Antonio J. Cuesta

The current available CMB data show an anomalously low value of the CMB temperature fluctuations at large angular scales (l < 40). This lack of power is not explained by the minimal LCDM model, and one of the possible mechanisms explored in…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-07 Simony Santos da Costa , Micol Benetti , Jailson Alcaniz
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