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相关论文: Bianchi Type VII_h Models and the WMAP 3-year Data

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In recent years the goal of estimating different cosmological parameters precisely has set new challenges in the effort to accurately measure the angular power spectrum of CMB. This has required removal of foreground contamination as well…

天体物理学 · 物理学 2008-11-26 Rajib Saha , Simon Prunet , Pankaj Jain , Tarun Souradeep

Bianchi-type string cosmology involves generalizations of the FRW backgrounds with three transitive spacelike Killing symmetries, but without any a priori assumption of isotropy in the 3D sections of homogeneity. With emphasis on those…

高能物理 - 理论 · 物理学 2009-10-28 N. A. Batakis

Full sky maps are made in five microwave frequency bands to separate the temperature anisotropy of the CMB from foreground emission. We define masks that excise regions of high foreground emission. The effectiveness of template fits to…

AIMS. Several authors have claimed to detect a significant cross-correlation between microwave WMAP anisotropies and the SDSS galaxy distribution. We repeat these analyses to determine the different cross-correlation uncertainties caused by…

宇宙学与河外天体物理 · 物理学 2015-05-18 M. Lopez-Corredoira , F. Sylos Labini , J. Betancort-Rijo

We study a specific correlation in spherical harmonic multipole domain for cosmic microwave background (CMB) analysis. This group of correlation between \Delta l=4n, n=1,2... is caused by symmetric signal in the Galactic coordinate system.…

天体物理学 · 物理学 2009-11-13 Pavel D. Naselsky , Igor D. Novikov , Lung-Yih Chiang

Correlated noise affects most astronomical datasets and to neglect accounting for it can lead to spurious signal detections, especially in low signal-to-noise conditions, which is often the context in which new discoveries are pursued. For…

天体物理仪器与方法 · 物理学 2020-07-01 J. -B. Delisle , N. Hara , D. Ségransan

We derive a constraint on patchy screening of the cosmic microwave background from inhomogeneous reionization, using off-diagonal TB and TT correlations in WMAP-7 temperature/polarization data. We interpret this as a constraint on the rms…

宇宙学与河外天体物理 · 物理学 2013-10-08 Vera Gluscevic , Marc Kamionkowski , Duncan Hanson

The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the full sky in Stokes I, Q, and U parameters at frequencies 23, 33, 41, 61, and 94 GHz. We detect correlations between the temperature and polarization maps significant at more…

天体物理学 · 物理学 2015-06-24 A. Kogut

We use a separable mode expansion estimator with WMAP data to estimate the bispectrum for all the primary families of non-Gaussian models. We review the late-time mode expansion estimator methodology which can be applied to any…

宇宙学与河外天体物理 · 物理学 2015-05-19 J. R. Fergusson , M. Liguori , E. P. S. Shellard

We systematically study antithetic initial noise in diffusion models, discovering that pairing each noise sample with its negation consistently produces strong negative correlation. This universal phenomenon holds across datasets, model…

机器学习 · 计算机科学 2026-02-02 Jing Jia , Sifan Liu , Bowen Song , Wei Yuan , Liyue Shen , Guanyang Wang

A considerable effort has recently gone into the study of Gaussianity of cosmic microwave background (CMB) data. Among such attempts, there is one with two non-Gaussianity indicators, proposed by the authors, and used in a search for…

宇宙学与河外天体物理 · 物理学 2009-07-10 A. Bernui , M. J. Reboucas

[Abridged] We have produced a cleaned map of the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data using an improved foreground subtraction technique. We perform an internal linear combination (ILC) to subtract the Galactic foreground…

天体物理学 · 物理学 2008-11-26 Chan-Gyung Park , Changbom Park , J. Richard Gott

Non-commutative geometry at inflation can give arise to parity violating modulations of the primordial power spectrum. We develop the statistical tools needed for investigating whether these modulations are evident in the Cosmic Microwave…

宇宙学与河外天体物理 · 物理学 2010-11-25 N. E. Groeneboom , M. Axelsson , D. F. Mota , T. Koivisto

Cross-modal retrieval methods are the preferred tool to search databases for the text that best matches a query image and vice versa. However, image-text retrieval models commonly learn to memorize spurious correlations in the training…

计算机视觉与模式识别 · 计算机科学 2023-04-10 Jae Myung Kim , A. Sophia Koepke , Cordelia Schmid , Zeynep Akata

The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB) radiation maps have detected ellipticity of the temperature anisotropy spots independent on the temperature threshold. The effect has been found for spots up to several…

Theories have revealed the universality of the band tilting effect in topological Weyl semimetals (WSMs) and its implications for the material's physical properties. However, the experimental identification of tilted Weyl bands remains much…

A directional spherical wavelet analysis is performed to examine the Gaussianity of the WMAP 1-year data. Such an analysis is facilitated by the introduction of a fast directional continuous spherical wavelet transform. The directional…

天体物理学 · 物理学 2008-03-04 J. D. McEwen , M. P. Hobson , A. N. Lasenby , D. J. Mortlock

Given two unidirectionally coupled nonlinear systems, we speak of generalized synchronization when the responder \textquotedblleft follows\textquotedblright\ the driver. Mathematically, this situation is implemented by a map from the driver…

混沌动力学 · 物理学 2025-02-13 José M. Amigó , Roberto Dale , Juan C. King , Klaus Lehnertz

[Abridged.] It is conceivable that no single statistical estimator can be sensitive to all forms and levels of non-Gaussianity that may be present in observed CMB data. In recent works a statistical procedure based upon the calculation of…

宇宙学与河外天体物理 · 物理学 2015-01-14 A. Bernui , M. J. Reboucas

Constraints on inflationary $B$-modes using Cosmic Microwave Background polarization data commonly rely on either template cleaning or cross-spectra between maps at different frequencies to disentangle galactic foregrounds from the…

宇宙学与河外天体物理 · 物理学 2018-02-28 Christopher Sheehy , Anže Slosar