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Related papers: Bianchi Type VII_h Models and the WMAP 3-year Data

200 papers

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…

Astrophysics · Physics 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…

High Energy Physics - Theory · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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.…

Astrophysics · Physics 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…

Instrumentation and Methods for Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Machine Learning · Computer Science 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Computer Vision and Pattern Recognition · Computer Science 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…

Astrophysics · Physics 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…

Chaotic Dynamics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Christopher Sheehy , Anže Slosar