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The cosmic microwave background (CMB), the relic radiation from the early Universe, offers a unique window into both primordial conditions and the intervening large-scale structure (LSS) it traverses. Interactions between CMB photons and…

宇宙学与河外天体物理 · 物理学 2025-01-24 Federico Bianchini , Abhishek S. Maniyar

We examine the extent to which galactic and extragalactic foregrounds can hamper the detection of primordial Cosmic Microwave Background (CMB) anisotropies. We limit our discussion to intermediate angular scales, $10^{\prime}\lsim \theta…

天体物理学 · 物理学 2009-09-25 L. Toffolatti

Most analysis of Cosmic Microwave Background spherical harmonic coefficients a_lm has focused on estimating the power spectrum C_l=<|a_lm|^2> rather than the coefficients themselves. We present a minimum-variance method for measuring a_lm…

天体物理学 · 物理学 2009-10-07 Angelica de Oliveira-Costa , Max Tegmark

The plane-mirror symmetry previously noticed in the Cosmic Microwave Background (CMB) temperature anisotropy maps of Wilkinson Microwave Anisotropy Probe is shown to possess certain anomalous properties. The degree of the randomness…

宇宙学与河外天体物理 · 物理学 2009-11-13 V. G. Gurzadyan , T. Ghahramanyan , A. L. Kashin , H. G. Khachatryan , A. A. Kocharyan , H. Kuloghlian , D. Vetrugno , G. Yegorian

Although commonly employed by X-ray astronomers, maximum likelihood estimators are known to be biased. In this paper we investigate the bias associated to the measure of the temperature from an X-ray thermal spectrum. We show that, in the…

天体物理学 · 物理学 2009-08-13 A. Leccardi , S. Molendi

An unbiased estimator for the ellipticity of an object in a noisy image is given in terms of the image moments. Three assumptions are made: i) the pixel noise is normally distributed, although with arbitrary covariance matrix, ii) the image…

宇宙学与河外天体物理 · 物理学 2017-08-09 Nicolas Tessore

The estimation of cosmological parameters from cosmic microwave experiments has almost always been performed assuming gaussian data. In this paper the sensitivity of the parameter estimation to different assumptions on the probability…

天体物理学 · 物理学 2009-11-07 Luca Amendola

Microwave background polarization, though presently undetected, is a fundamental prediction of any viable cosmological model. These lectures review the theoretical description of polarization, its physical interpretation, and potentially…

天体物理学 · 物理学 2011-04-15 Arthur Kosowsky

Cosmic microwave background (CMB) anisotropy is our richest source of cosmological information; the standard cosmological model was largely established thanks to study of the temperature anisotropies. By the end of the decade, the Planck…

天体物理学 · 物理学 2009-11-11 James G. Bartlett

Unbiased estimation for parameters of maximal distribution is a very fundamental problem in the statistical theory of sublinear expectation. In this paper, we proved that the maximum estimator is the largest unbiased estimator for the upper…

概率论 · 数学 2016-11-28 Hanqing Jin , Shige Peng

I describe briefly the Cosmic Microwave Background (hereafter CMB) physics which explains why high accuracy observations of its spatial structure are a unique observational tool both for the determination of the global cosmological…

天体物理学 · 物理学 2007-05-23 Francois R. Bouchet

Recent estimates of cosmological parameters derived from Cosmic Microwave Background (CMB) anisotropies are based on the assumption that we know the precise amount of energy density in relativistic particles in the universe, $\omega_{rel}$,…

天体物理学 · 物理学 2008-11-26 R. Bowen , S. H. Hansen , A. Melchiorri , J. Silk , R. Trotta

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…

高能物理 - 唯象学 · 物理学 2011-02-16 Subir Sarkar

In addition to its spectrum and temperature anisotropy, the 2.7K Cosmic Microwave Background is also expected to exhibit a low level of polarization. The spatial power spectrum of the polarization can provide details about the formation of…

天体物理学 · 物理学 2009-10-30 Brian Keating , Peter Timbie , Alexander Polnarev , Julia Steinberger

The current suite of results from Cosmic Microwave Background anisotropy experiments is fulfilling the promise of providing extraordinary levels of discrimination between cosmological models. We calculate a binned anisotropy power spectrum,…

天体物理学 · 物理学 2007-05-23 Elena Pierpaoli , Douglas Scott , Martin White

Large-scale cosmic microwave background anisotropies in homogeneous, globally anisotropic cosmologies are investigated. We perform a statistical analysis in which the four-year data from the Cosmic Background Explorer satellite is searched…

天体物理学 · 物理学 2008-11-26 Emory. F. Bunn , Pedro Ferreira , Joseph Silk

Recently funded satellites will map the cosmic microwave background radiation with unprecedented sensitivities and angular resolutions. Assuming only primordial adiabatic scalar and tensor perturbations, we evaluate how accurately…

天体物理学 · 物理学 2009-10-28 Arthur Kosowsky , Marc Kamionkowski , Gerard Jungman , David N. Spergel

This article describes the computation of cosmic microwave background anisotropies in a universe with multi-connected spatial sections and focuses on the implementation of the topology in standard CMB computer codes. The key ingredient is…

天体物理学 · 物理学 2009-11-07 Alain Riazuelo , Jean-Philippe Uzan , Roland Lehoucq , Jeffrey Weeks

We derive optimal estimators for the two-, three-, and four-point correlators of statistically isotropic scalar fields defined on the sphere, such as the Cosmic Microwave Background temperature fluctuations, allowing for arbitrary (linear)…

宇宙学与河外天体物理 · 物理学 2023-06-28 Oliver H. E. Philcox

We review the theory of the temperature anisotropy and polarization of the cosmic microwave background (CMB) radiation, and describe what we have learned from current CMB observations. In particular, we discuss how the CMB is being used to…

宇宙学与河外天体物理 · 物理学 2010-02-22 Anthony Challinor , Hiranya Peiris