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Features in the primordial power spectrum have been suggested as an explanation for glitches in the angular power spectrum of temperature anisotropies measured by the WMAP satellite. However, these glitches might just as well be artifacts…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Jan Hamann , Arman Shafieloo , Tarun Souradeep

The preferred shape for the primordial spectrum of curvature perturbations is determined by performing a Bayesian model selection analysis of cosmological observations. We first reconstruct the spectrum modelled as piecewise linear in \log…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-27 J. Alberto Vazquez , M. Bridges , M. P. Hobson , A. N. Lasenby

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

We consider the possibility that the primordial curvature perturbation is direction-dependent. To first order this is parameterised by a quadrupolar modulation of the power spectrum and results in statistical anisotropy of the CMB, which…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-15 Amel Durakovic , Paul Hunt , Suvodip Mukherjee , Subir Sarkar , Tarun Souradeep

We study the capability of future measurements of the galaxy clustering power spectrum to probe departures from a power-law spectrum for primordial fluctuations. On considering the information from the galaxy clustering power spectrum up to…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-05 Mario Ballardini , Fabio Finelli , Cosimo Fedeli , Lauro Moscardini

We update the constraints on possible features in the primordial inflationary density perturbation spectrum by using the latest data from the WMAP7 and ACT Cosmic Microwave Background experiments. The inclusion of new data significantly…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Micol Benetti , Massimiliano Lattanzi , Erminia Calabrese , Alessandro Melchiorri

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

We investigate how well galaxy cluster number counts can constrain the primordial power spectrum. Measurements of the primary anisotropies in the cosmic microwave background (CMB) may be limited, by the presence of foregrounds from…

Astrophysics · Physics 2015-03-13 Teeraparb Chantavat , Christopher Gordon , Joseph Silk

Combining Planck CMB temperature [1] and BICEP2 B-mode polarization data [2,3] we show qualitatively that, assuming inflationary consistency relation, the power-law form of the scalar primordial spectrum is ruled out at more than $3\sigma$…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-17 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

We present three non-parametric Bayesian primordial reconstructions using Planck 2018 polarization data: linear spline primordial power spectrum reconstructions, cubic spline inflationary potential reconstructions and sharp-featured…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-20 Will J. Handley , Anthony N. Lasenby , Hiranya V. Peiris , Michael P. Hobson

In this work we explore the power of future large-scale surveys to constrain possible deviations from the standard single-field slow-roll inflationary scenario. Specifically, we parametrize possible fluctuations around the almost…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-14 Muhammad Sadegh Esmaeilian , Marzieh Farhang , Shirin Khodabakhshi

We undertake a thorough search for signatures of sharp oscillatory features in the WMAP9 power spectrum and bispectrum as well as in the Planck power spectrum. For the first time, we carry out searches in both the power spectrum and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 J. R. Fergusson , H. F. Gruetjen , E. P. S. Shellard , B. Wallisch

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 constrain the shape of the primordial power spectrum using recent measurements of the cosmic microwave background (CMB) from the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year data and other high-resolution CMB experiments. We also…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-27 J. Alberto Vazquez , A. N. Lasenby , M. Bridges , M. P. Hobson

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

We perform a Bayesian analysis to study possible features in the primordial inflationary power spectrum of scalar perturbations. In particular, we analyse the possibility of detecting the imprint of these primordial features in the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Micol Benetti , Jailson S. Alcaniz

We investigate a set of cosmological models for which the primordial power spectrum has a large-scale power deficit. The standard power-law spectrum is subject to long-wavelength modifications described by some new parameters, resulting in…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Sandro D. P. Vitenti , Patrick Peter , Antony Valentini

The enormous red-shifting of the modes during the inflationary epoch suggests that physics at the very high energy scales may modify the primordial perturbation spectrum. Therefore, the measurements of the anisotropies in the Cosmic…

High Energy Physics - Theory · Physics 2015-06-26 S. Shankaranarayanan , L. Sriramkumar

The primordial curvature fluctuation spectrum is reconstructed by the maximum likelihood reconstruction method using the five-year Wilkinson Microwave Anisotropy Probe data of the cosmic microwave background temperature anisotropy. We apply…

Astrophysics · Physics 2009-02-19 Ryo Nagata , Jun'ichi Yokoyama

We constrain the primordial fluctuation spectrum P(k) by using the new data on the Cosmic Microwave Background (CMB) from the Boomerang and MAXIMA experiments. Our study is based on slow-roll inflationary models, and we consider the…

Astrophysics · Physics 2009-10-31 S. Hannestad , S. H. Hansen , F. L. Villante