English
Related papers

Related papers: Reconstructing the Primordial Power Spectrum

200 papers

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

We present a new probe of purely gravitationally coupled sectors with large anisotropies. These anisotropies are damped via gravitational interactions with the baryon-photon fluid, which is heated up in the process. The injected heat causes…

High Energy Physics - Phenomenology · Physics 2023-02-16 Nicklas Ramberg , Wolfram Ratzinger , Pedro Schwaller

The lecture is devoted to the comparison of a few models of cosmic recombination kinetics with recent CMB anisotropy data and to corresponding predictions for the upcoming PLANCK mission. The influence of additional sources of ionized…

Astrophysics · Physics 2007-05-23 Pavel D. Naselsky

In the last few decades, advances in observational cosmology have given us a standard model of cosmology. We know the content of the universe to within a few percent. With more ambitious experiments on the way, we hope to move beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-26 Amit P. S. Yadav , Benjamin D. Wandelt

Cosmic microwave background anisotropies encode crucial information about the early Universe and fundamental cosmological physics. Although the standard $\Lambda$CDM model provides a successful description of cosmic evolution, persistent…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Yang Han , Lu Chen , Guo-Hao Li , Pei-Yuan Xu

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

Measuring spectral distortions (SDs) of the cosmic microwave background (CMB) will provide new constraints on previously unexplored scales of the primordial power spectrum, allowing us to extend the probed parameter space by several orders…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-03 Nils Schöneberg , Matteo Lucca , Deanna C. Hooper

The hemispherical power asymmetry in the cosmic microwave background may be explained by the modulation of some primordial cosmological parameter, such as the sound speed of the inflaton. This modulation can be achieved by the perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-20 Yi-Fu Cai , Wen Zhao , Yang Zhang

The primordial magnetic field (PMF) can strongly affect the cosmic microwave background (CMB) power spectrum and the formation of large scale structure. In this presentation, we calculate the CMB temperature anisotropies generated by…

Astrophysics · Physics 2008-11-26 Dai G. Yamazaki , Kiyotomo Ichiki , Toshitaka Kajino , Grant J. Mathews

The evolution of small scale cosmological perturbations is carefully re-examined. Through the interaction with photons via electrons, baryon perturbations show interesting behavior in some physical scales. Characteristic features of the…

Astrophysics · Physics 2009-10-30 Kazuhiro Yamamoto , Naoshi Sugiyama , Humitaka Sato

Precision measurements of anisotropies in the cosmic microwave background and of the clustering of large-scale structure have supposedly confirmed that the primordial density perturbation has a (nearly) scale-invariant spectrum. However…

High Energy Physics - Phenomenology · Physics 2011-02-16 Subir Sarkar

A complete numerical calculation of the temperature anisotropies and the polarization of the cosmic microwave background (CMB) is presented for a non zero cross correlation of a stochastic magnetic field with the primordial curvature…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-15 Kerstin E. Kunze

The bulk of recent cosmological research has focused on the adiabatic cold dark matter model and its simple extensions. Here we present an accurate fitting formula that describes the matter transfer functions of all common variants,…

Astrophysics · Physics 2009-10-30 Daniel J. Eisenstein , Wayne Hu

In this paper we implement an improved (error sensitive) Richardson-Lucy deconvolution algorithm on the measured angular power spectrum from the WMAP 3 year data to determine the primordial power spectrum assuming different points in the…

Astrophysics · Physics 2008-12-18 Arman Shafieloo , Tarun Souradeep

We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum, which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field. We find new configurations in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-03 Maresuke Shiraishi , Shuichiro Yokoyama

We show that the difference between the theoretically expected and measured by WMAP amplitude of the quadrupole fluctuations of CMB can be related to the impact of the anisotropic curvature of the homogeneous universe dominated by the dark…

Astrophysics · Physics 2008-11-26 M. Demiański , A. G. Doroshkevich

Prospects for testing the adiabaticity of the primordial cosmological perturbations using MAP and PLANCK are evaluated. The most general cosmological perturbation in a universe with just baryons, photons, neutrinos, and a cold dark matter…

Astrophysics · Physics 2009-10-31 Martin Bucher , Kavilan Moodley , Neil Turok

We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. These constraints are very powerful around or just after…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-28 Vivian Poulin , Julien Lesgourgues , Pasquale D. Serpico

Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Cheng Cheng , Qing-Guo Huang

We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological…

High Energy Physics - Phenomenology · Physics 2009-11-07 Irit Maor , Ram Brustein