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We investigate signatures of neutrino scattering in the Cosmic Microwave Background (CMB) and matter power spectra, and the extent to which present cosmological data can distinguish between a free streaming or tightly coupled fluid of…

天体物理学 · 物理学 2007-05-23 Nicole F. Bell , Elena Pierpaoli , Kris Sigurdson

Anisotropies in the cosmic microwave background radiation due to gravity waves are investigated. An initial spectrum of gravity waves may have been induced during an epoch of inflation. We study the propagation of such a spectrum in a…

天体物理学 · 物理学 2008-02-03 Ruth Durrer , Tina Kahniashvili

We investigate the effect of wiggly cosmic strings on the cosmic microwave background radiation anisotropy and matter power spectrum by modifying the string network model used by Albrecht et al.. We employ the wiggly equation of state for…

天体物理学 · 物理学 2016-08-25 Levon Pogosian , Tanmay Vachaspati

We propose a method to extract the projected power spectrum of density perturbations from the distortions in the cosmic microwave background (CMB). The distortions are imprinted onto the CMB by the gravitational lensing effect and can be…

天体物理学 · 物理学 2009-10-31 Uros Seljak , Matias Zaldarriaga

The recent measurements of the power spectrum of Cosmic Microwave Background anisotropies are consistent with the simplest inflationary scenario and big bang nucleosynthesis constraints. However, these results rely on the assumption of a…

天体物理学 · 物理学 2009-11-07 Carolina J. Odman , Alessandro Melchiorri , Michael P. Hobson , Anthony N. Lasenby

The standard inflationary model presents a simple scenario within which the homogeneity, isotropy and flatness of the universe appear as natural outcomes and, in addition, fluctuations in the energy density are originated during the…

天体物理学 · 物理学 2023-03-08 E. Martinez-Gonzalez , P. Vielva

This paper covers several techniques of intercomparison of Cosmic Microwave Background (CMB) anisotropy experiments and models of structure formation. It presents the constraints on several cosmological parameters using current CMB…

天体物理学 · 物理学 2007-05-23 Graca Rocha

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

天体物理学 · 物理学 2009-11-06 Masahiro Kawasaki , Takeo Moroi , Tomo Takahashi

The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has…

天体物理学 · 物理学 2011-04-11 Tarun Souradeep , Rajib Saha , Pankaj Jain

Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~1000. The angular power spectra of temperature and polarisation fluctuations are…

天体物理学 · 物理学 2009-11-10 Marco Bersanelli , Davide Maino , Aniello Mennella

We present a new, model-independent approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern. Our approach is based on the empirical distribution function of the normalized spherical harmonic…

天体物理学 · 物理学 2011-05-10 Frode K. Hansen , Domenico Marinucci , Paolo Natoli , Nicola Vittorio

We devise a measure n(r) to quantify a robust feature in the coherent cosmic perturbations, namely the narrowness of the first peak in the power spectrum of the Cosmic Microwave Background (CMB) anisotropy. A maximum-likelihood analysis…

天体物理学 · 物理学 2007-05-23 Jiun-Huei Proty Wu

Gaussianity of the cosmological perturbations in the universe is one of the key predictions of standard inflation, but it is violated by other models of structure formation such as topological defects. We present the first test of the…

We investigate the cosmological information in higher-order statistics of the cosmic microwave background (CMB) lensing convergence field for a near-term experiment with noise properties similar to the Simons Observatory (SO). Using a fully…

宇宙学与河外天体物理 · 物理学 2026-03-16 Shu-Fan Chen , J. Colin Hill , Zoltán Haiman

We demonstrate that creation of dark-matter particles at a constant rate implies the existence of a cosmological term that decays linearly with the Hubble rate. We discuss the cosmological model that arises in this context and test it…

宇宙学与河外天体物理 · 物理学 2012-09-04 J. S. Alcaniz , H. A. Borges , S. Carneiro , J. C. Fabris , C. Pigozzo , W. Zimdahl

Physical models for the hemispherical power asymmetry in the cosmic microwave background (CMB) reported by the Planck Collaboration must satisfy CMB constraints to the homogeneity of the Universe and quasar constraints to power asymmetries.…

宇宙学与河外天体物理 · 物理学 2013-06-26 Liang Dai , Donghui Jeong , Marc Kamionkowski , Jens Chluba

We give a brief review of the known effects of a dynamical vacuum cosmological component, the dark energy, on the anisotropies of the cosmic microwave background (CMB). We distinguish between a "classic" class of observables, used so far to…

天体物理学 · 物理学 2009-09-01 Carlo Baccigalupi , Viviana Acquaviva

The spectral variation of the cosmic microwave background (CMB) as observed by WMAP was tested using foreground reduced WMAP5 data, by producing subtraction maps at the 1$^\circ$ angular resolution between the two cosmological bands of V…

宇宙学与河外天体物理 · 物理学 2015-05-13 Bi-Zhu Jiang , Richard Lieu , Shuang-Nan Zhang , Bart Wakker

The effect of weak gravitational lensing on the cosmic microwave background (CMB) temperature anisotropies and polarization will provide access to cosmological information that cannot be obtained from the primary anisotropies alone. We…

天体物理学 · 物理学 2007-05-23 Sarah Smith , Anthony Challinor , Graca Rocha

In this review, we give an overview of some of the major aspects of data reduction and analysis for the cosmic microwave background (CMB). Since its prediction and discovery in the last century, the CMB radiation has proven itself to be one…

天体物理学 · 物理学 2009-09-29 Matthieu Tristram , Ken Ganga