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相关论文: Analysis of CMB maps with 2D wavelets

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Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

宇宙学与河外天体物理 · 物理学 2023-05-23 Md Ishaque Khan , Rajib Saha

ABRIDGED: We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the WMAP CMB foreground reduced, temperature maps, and cross-channel difference maps. We divide the sky into regions of varying…

天体物理学 · 物理学 2009-06-23 Bartosz Lew

Observations of the cosmic microwave background (CMB), especially of its frequency spectrum and its anisotropies, both in temperature and in polarization, have played a key role in the development of modern cosmology and our understanding…

宇宙学与河外天体物理 · 物理学 2015-01-20 Martin Bucher

We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

宇宙学与河外天体物理 · 物理学 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

The statistical properties of the temperature anisotropies and polarization of the of cosmic microwave background (CMB) radiation offer a powerful probe of the physics of the early universe. In recent works a statistical procedure based…

宇宙学与河外天体物理 · 物理学 2017-03-15 M. J. Reboucas , A. Bernui

We test anisotropic dark energy models with the 7-year WMAP temperature observations data. In the presence of imperfect sources, due to large-scale gradients or anisotropies in the dark energy field, the CMB sky will be distorted…

宇宙学与河外天体物理 · 物理学 2014-05-08 Magnus J. Axelsson , Frode K. Hansen , Tomi Koivisto , David F. Mota

The study of cosmic birefringence through Cosmic Microwave Background (CMB) experiments is a key research area in cosmology and particle physics, providing a critical test for Lorentz and CPT symmetries. This paper focuses on an upcoming…

宇宙学与河外天体物理 · 物理学 2025-04-18 Yiwei Zhong , Hongbo Cai , Si-Yu Li , Yang Liu , Mingzhe Li , Wenjuan Fang

We simulate the anisotropy in the cosmic microwave background (CMB) induced by cosmic strings. By numerically evolving a network of cosmic strings we generate full-sky CMB temperature anisotropy maps. Based on $192$ maps, we compute the…

天体物理学 · 物理学 2008-11-26 B. Allen , R. R. Caldwell , E. P. S. Shellard , A. Stebbins , S. Veeraraghavan

Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the…

宇宙学与河外天体物理 · 物理学 2025-07-22 Mariona Giner Mascarell , Emory F. Bunn

In this lecture, after a synthetic review of measurements of CMB temperature anisotropies and of their cosmological implications, the theoretical background of CMB polarization is summarized and the concepts of the main experiments that are…

宇宙学与河外天体物理 · 物理学 2018-02-14 Gianfranco De Zotti

Recent results of the ESA Planck satellite have confirmed the existence of some anomalies in the statistical distribution of the cosmic microwave background (CMB) anisotropies. One of the most intriguing anomalies is the Cold Spot, firstly…

宇宙学与河外天体物理 · 物理学 2015-06-16 R. Fernández-Cobos , P. Vielva , E. Martínez-González , M. Tucci , M. Cruz

We present an efficient method to compute CMB anisotropies in non-flat universes. First we derive the Boltzmann equation for cosmic microwave background temperature and polarization fluctuations produced by scalar perturbations in a general…

天体物理学 · 物理学 2009-06-16 Matias Zaldarriaga , Uros Seljak , Edmund Bertschinger

We report the results from the second flight of QMAP, an experiment to map the cosmic microwave background near the North Celestial Pole. We present maps of the sky at 31 and 42 GHz as well as a measurement of the angular power spectrum…

天体物理学 · 物理学 2009-10-30 Tom Herbig , Angelica de Oliveira-Costa , Mark Devlin , Amber Miller , Lyman Page , Max Tegmark

We present a pedagogical and phenomenological introduction to the study of cosmic microwave background (CMB) polarization to build intuition about the prospects and challenges facing its detection. Thomson scattering of temperature…

天体物理学 · 物理学 2009-08-18 Wayne Hu , Martin White

We search the high-latitude portion of the COBE Differential Microwave Radiometers (DMR) 4-year sky maps for evidence of a non-Gaussian temperature distribution in the cosmic microwave background. The genus, 3-point correlation function,…

天体物理学 · 物理学 2009-10-28 A. Kogut , A. J. Banday , C. L. Bennett , K. Gorski , G. Hinshaw , G. F. Smoot , E. L. Wright

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

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…

宇宙学与河外天体物理 · 物理学 2012-03-06 Duncan Hanson , Antony Lewis

Despite the fact that the physics of the cosmic microwave background anisotropies is most naturally expressed in Fourier space, pixelised maps are almost always used in the analysis and simulation of microwave data. A complementary approach…

We use Nambu-Goto numerical simulations to compute the cosmic microwave background (CMB) temperature anisotropies induced at arcminute angular scales by a network of cosmic strings in a Friedmann-Lemaitre-Robertson-Walker (FLRW) expanding…

天体物理学 · 物理学 2008-11-26 Aurélien A. Fraisse , Christophe Ringeval , David N. Spergel , François R. Bouchet

Anisotropies in distortions to the frequency spectrum of the cosmic microwave background (CMB) can be created through spatially varying heating processes in the early Universe. For instance, the dissipation of small-scale acoustic modes…

宇宙学与河外天体物理 · 物理学 2017-01-25 Jens Chluba , Emanuela Dimastrogiovanni , Mustafa A. Amin , Marc Kamionkowski