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相关论文: The Impact of Secondary non-Gaussianities in the C…

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The non-Gaussianity of inflationary perturbations, as encoded in the bispectrum (or 3-point correlator), has become an important additional way of distinguishing between inflation models, going beyond the linear Gaussian perturbation…

宇宙学与河外天体物理 · 物理学 2021-07-23 Bartjan van Tent

Skewness of temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational…

天体物理学 · 物理学 2009-10-28 Dipak Munshi , Tarun Souradeep , Alexei A. Starobinsky

We consider five dimensional conformal gravity theory which describes an anisotropic extra dimension. Reducing the theory to four dimensions yields Brans-Dicke theory with a potential and a hidden parameter $z$ which implements the…

宇宙学与河外天体物理 · 物理学 2018-01-23 Seyen Kouwn , Phillial Oh , Chan-Gyung Park

We develop a systematic and unified approach to estimate all possible secondary (i.e. non-primordial) nonlinear effects to the cosmic microwave background (CMB) polarization, named curve-of-sight integration approach. In this approach, the…

宇宙学与河外天体物理 · 物理学 2021-10-20 Toshiya Namikawa , Atsushi Naruko , Ryo Saito , Atsushi Taruya , Daisuke Yamauchi

The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation.…

天体物理学 · 物理学 2009-10-22 Alejandro Gangui

We examine stochastic temperature fluctuations of the cosmic background radiation (CBR) arising via the Sachs-Wolfe effect from gravitational wave perturbations produced in the early universe. These temperature fluctuations are described by…

天体物理学 · 物理学 2009-10-22 Bruce Allen , Scott Koranda

In this paper we show how the rescattering of CMB photons after cosmic reionization can give a significant linear contribution to the temperature-matter cross-correlation measurements. These anisotropies, which arise via a late time Doppler…

天体物理学 · 物理学 2008-11-26 Tommaso Giannantonio , Robert Crittenden

We introduce a non-Gaussian model of structure formation, and show how it produces surprising sampling effects on the estimation of the CMB power spectrum. Estimates of the average power spectrum based on small sky patches produce…

天体物理学 · 物理学 2009-10-30 Charlotte Cheung , Joao Magueijo

Much recent work on the cosmic microwave background (CMB) has focussed on the angular power spectrum of temperature anisotropies and particularly on the recovery of cosmological parameters from acoustic peaks in the power spectrum. However,…

天体物理学 · 物理学 2007-05-23 Marc Kamionkowski

We study the nonlinear effects of minimally coupled, massless, cosmological scalar fields on the cosmic microwave background (CMB). These fields can exhibit post-recombination parametric resonance and subsequent nonlinear evolution leading…

宇宙学与河外天体物理 · 物理学 2023-04-20 Tristan L. Smith , John T. Giblin , Mustafa A. Amin , Mary Gerhardinger , Ericka Florio , Matthew Cerep , Shar Daniels

Why is non-Gaussianity interesting? One of generic predictions from inflationary scenarios is that primordial fluctuations are exactly Gaussian in linear order; however, the non-linearity in the inflation will produce weak non-Gaussianity.…

天体物理学 · 物理学 2017-08-23 Eiichiro Komatsu , David N. Spergel

Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol…

宇宙学与河外天体物理 · 物理学 2012-10-02 Sudeep Das , Eric V. Linder

Working toward a model independent understanding of cosmic microwave background (CMB) anisotropies and their significance, we undertake a comprehensive and self-contained study of scalar perturbation theory. Initial conditions, evolution,…

天体物理学 · 物理学 2009-09-25 Wayne Hu , Naoshi Sugiyama

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark…

天体物理学 · 物理学 2016-01-13 J. Richard Bond , George Efstathiou , Max Tegmark

When fitting cosmological models to data, a Bayesian framework is commonly used, requiring assumptions on the form of the likelihood and model prior. In light of current tensions between different data, it is interesting to investigate the…

宇宙学与河外天体物理 · 物理学 2024-10-31 Jordan Krywonos , Simone Paradiso , Alex Krolewski , Shahab Joudaki , Will Percival

Cosmic Microwave Background (CMB) Anisotropies is a subject of intensive research in several fields of sciences. In this paper we start a systematic development of basic notions and theory in statistics according to the application for CMB.…

应用统计 · 统计学 2013-12-30 Gyorgy Terdik

We present an analytic approach to the estimation of beam asymmetry effects in CMB temperature and linear polarization anisotropy experiments. We derive via perturbative expansions simple and accurate results for the case of an elliptical…

天体物理学 · 物理学 2009-11-06 P. Fosalba , O. Doré , F. R. Bouchet

Bouncing models of cosmology, as they arise e.g. in loop quantum cosmology, can be followed by an inflationary phase and generate close-to-scale-invariant fluctuation spectra as observed in the Cosmic Microwave Background (CMB). However,…

宇宙学与河外天体物理 · 物理学 2023-05-12 Bartjan van Tent , Paola C. M. Delgado , Ruth Durrer

We present a new, more powerful and accurate, analytic treatment of cosmic microwave background (CMB) anisotropies in the weakly coupled regime. Three applications are presented: gravitational redshifts in a time dependent potential, the…

天体物理学 · 物理学 2008-11-26 Wayne Hu , Martin White

The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…

天体物理学 · 物理学 2011-04-15 Ruth Durrer