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相关论文: New Geometric Representations of the CMB 2pcf

200 篇论文

Anomalies in the large-scale CMB temperature sky measured by WMAP have been suggested as possible evidence for a violation of statistical isotropy on large scales. In any physical model for broken isotropy, there are testable consequences…

天体物理学 · 物理学 2008-12-18 Cora Dvorkin , Hiranya V. Peiris , Wayne Hu

Search for the statistical anisotropy in the CMB data is a powerful tool for constraining models of the early Universe. In this paper we focus on the recently proposed cosmological scenario with conformal rolling. We consider two…

宇宙学与河外天体物理 · 物理学 2015-06-04 S. R. Ramazanov , G. I. Rubtsov

We propose several pseudoentropy measures that agree well with the Wehrl entropy, but are significantly faster to compute. All of them are rotationally invariant measures of entanglement very sensitive to non-Gaussianity, anisotropy, and…

宇宙学与河外天体物理 · 物理学 2019-05-06 Momchil Minkov , Marvin Pinkwart , Peter Schupp

We present an assessment of the CMB large scale anomalies in polarisation using the two-point correlation function as a test case. We employ the state of the art of large scale polarisation datasets: the first based on a Planck 2018 HFI 100…

宇宙学与河外天体物理 · 物理学 2021-08-25 Caterina Chiocchetta , Alessandro Gruppuso , Massimiliano Lattanzi , Paolo Natoli , Luca Pagano

We study the Planck CMB temperature at different scales through its derivatives up to second order, which allows one to characterize the local shape and isotropy of the field. The problem of having an incomplete sky in the calculation and…

宇宙学与河外天体物理 · 物理学 2017-02-22 A. Marcos-Caballero , E. Martínez-González , P. Vielva

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

We consider the issue of characterizing the coherent large-scale patterns from CMB temperature maps in globally anisotropic cosmologies. The methods we investigate are reasonably general; the particular models we test them on are the…

宇宙学与河外天体物理 · 物理学 2015-05-18 Rockhee Sung , Jo Short , Peter Coles

The origin of small deviations from statistical isotropy in the Cosmic Microwave Background (CMB) - the so-called CMB anomalies - remains an open question in modern cosmology. In this work, we test statistical isotropy in Planck Data…

宇宙学与河外天体物理 · 物理学 2025-04-09 C. Gimeno-Amo , F. K. Hansen , E. Martínez-González , R. B. Barreiro , A. J. Banday

Recent observations opened up a new window on the inflationary model building. As it was firstly reported by the WMAP data, there may be some indications of statistical anisotropy on the CMB map, although the statistical significance of…

宇宙学与河外天体物理 · 物理学 2015-11-06 Razieh Emami

In this work we investigate the standard deviation of the Cosmic Microwave Background (CMB) temperature gradient field as a signature for a multiply connected nature of the Universe. CMB simulations of a spatially infinite universe model…

宇宙学与河外天体物理 · 物理学 2021-11-02 Ralf Aurich , Thomas Buchert , Martin J. France , Frank Steiner

The statistical expectation values of the temperature fluctuations of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. This assumption of {\em statistical isotropy} (SI) of the CMB anisotropy should…

天体物理学 · 物理学 2009-11-10 Amir Hajian , Tarun Souradeep

We present a simple, yet accurate approximation for calculating the cosmic microwave background anisotropy power spectrum in adiabatic models. It consists of solving for the evolution of a two-fluid model until the epoch of recombination…

天体物理学 · 物理学 2009-10-22 Uros Seljak

Measurements of CMB anisotropy are ideal experiments for discovering the non-trivial global topology of the universe. To evaluate the CMB anisotropy in multiply-connected compact cosmological models, one needs to compute eigenmodes of the…

天体物理学 · 物理学 2007-05-23 Kaiki Taro Inoue

It has been argued recently by Copi etal (2009) that the lack of large angular correlations of the CMB temperature field provides strong evidence against the standard, statistically isotropic, inflationary LambdaCDM cosmology. We compare…

宇宙学与河外天体物理 · 物理学 2015-05-14 George Efstathiou , Yin-Zhe Ma , Duncan Hanson

We measure the angular bispectrum of the cosmic microwave background (CMB) radiation anisotropy from the COBE Differential Microwave Radiometer (DMR) four-year sky maps. The angular bispectrum is the harmonic transform of the three-point…

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

The properties of the Cosmic Microwave Background (CMB) maps carry valuable cosmological information. Here we report the results of the analysis hot and cold CMB anisotropy spots in the BOOMERanG 150 GHz map in terms of number, area,…

We examine all-sky cosmic microwave background (CMB) temperature maps on large angular scales to compare their consistency with two scenarios: the standard inflationary quantum picture, and a distribution constrained to have a universal…

宇宙学与河外天体物理 · 物理学 2022-04-13 Nathaniel Selub , Frederick Wehlen , Craig Hogan , Stephan S. Meyer

We perform an analysis of the CMB temperature data taken by the Planck satellite investigating if there is any significant deviation from cosmological isotropy. We look for differences in the spectrum between two opposite hemispheres and…

宇宙学与河外天体物理 · 物理学 2015-01-14 Miguel Quartin , Alessio Notari

Cosmic microwave background measurements show an agreement with the concordance cosmology model except for a few notable anomalies: Power Suppression, the lack of large scale power in the temperature data compared to what is expected in the…

宇宙学与河外天体物理 · 物理学 2019-08-20 Shabbir Shaikh , Suvodip Mukherjee , Santanu Das , Benjamin D. Wandelt , Tarun Souradeep