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We present efficient algorithms for CMB lensing simulation and power spectrum es- timation for flat-sky CMB polarization maps. We build a pure B-mode estimator to remedy E to B leakage due to partial sky coverage. We show that our…

宇宙学与河外天体物理 · 物理学 2013-11-14 Thibaut Louis , Sigurd Næss , Sudeep Das , Joanna Dunkley , Blake Sherwin

We introduce a novel neural network, SkyReconNet, which combines the expanded receptive fields of dilated convolutional layers along with standard convolutions, to capture both the global and local features for reconstructing the missing…

宇宙学与河外天体物理 · 物理学 2025-05-26 Reyhan D. Lambaga , Vipin Sudevan , Pisin Chen

Detection of magnetic-type ($B$-type) polarization in the Cosmic Microwave Background (CMB) radiation plays a crucial role in probing the relic gravitational wave (RGW) background. In this paper, we propose a new method to deconstruct a…

宇宙学与河外天体物理 · 物理学 2015-03-17 Wen Zhao , Deepak Baskaran

The cosmic microwave background (CMB) is a significant source of knowledge about the origin and evolution of our universe. However, observations of the CMB are contaminated by foreground emissions, obscuring the CMB signal and reducing its…

机器学习 · 计算机科学 2023-02-27 Jadie Adams , Steven Lu , Krzysztof M. Gorski , Graca Rocha , Kiri L. Wagstaff

This paper is concerned with small angular scale experiments for the observation of cosmic microwave background anisotropies. In the absence of beam, the effects of partial coverage and pixelisation are disentangled and analyzed (using…

天体物理学 · 物理学 2009-11-07 J. V. Arnau , A. M. Aliaga , D. Saez

This work describes Cosmic Microwave Background (CMB) data analysis algorithms and their implementations, developed to produce a pixelized map of the sky and a corresponding pixel-pixel noise correlation matrix from time ordered data for a…

We present a method designed to estimate the noise power spectrum in the time domain for CMB experiments. The noise power spectrum is extracted from the time ordered data avoiding the contamination coming from sky signal and accounting the…

天体物理学 · 物理学 2009-11-10 Alexandre Amblard , Jean-Christophe Hamilton

Although the broad outlines of the appropriate pipeline for cosmological likelihood analysis with CMB data has been known for several years, only recently have we had to contend with the full, large-scale, computationally challenging…

天体物理学 · 物理学 2009-11-10 Andrew H. Jaffe , J. R. Bond , P. G. Ferreira , L. E. Knox

Analysis and denoising of Cosmic Microwave Background (CMB) maps are performed using wavelet multiresolution techniques. The method is tested on $12^{\circ}.8\times 12^{\circ}.8$ maps with resolution resembling the experimental one expected…

天体物理学 · 物理学 2009-10-31 J. L. Sanz , F. Argueso , L. Cayon , E. Martinez-Gonzalez , R. B. Barreiro , L. Toffolatti

We describe and implement an exact, flexible, and computationally efficient algorithm for joint component separation and CMB power spectrum estimation, building on a Gibbs sampling framework. Two essential new features are 1) conditional…

天体物理学 · 物理学 2010-11-11 H. K. Eriksen , J. B. Jewell , C. Dickinson , A. J. Banday , K. M. Gorski , C. R. Lawrence

We describe a new numerical algorithm to obtain high-resolution simulated maps of the Cosmic Microwave Background (CMB), for a broad class of non-Gaussian models. The kind of non-Gaussianity we account for is based on the simple idea that…

天体物理学 · 物理学 2009-11-07 Michele Liguori , Sabino Matarrese , Lauro Moscardini

The {\it COBE} DMR sky maps contain low-level correlated noise. We obtain estimates of the amplitude and pattern of the correlated noise from three techniques: angular averages of the covariance matrix, Monte Carlo simulations of two-point…

Modelling of the weak lensing of the CMB will be crucial to obtain correct cosmological parameter constraints from forthcoming precision CMB anisotropy observations. The lensing affects the power spectrum as well as inducing…

天体物理学 · 物理学 2010-11-17 Antony Lewis

We show that the popular ILC approach is unstable in respect to the division of the sample of map pixels to the set of ``homogeneous'' subsamples. For suitable choice of such subsamples we can obtain the restored CMB signal with amplitudes…

宇宙学与河外天体物理 · 物理学 2011-02-18 A. Doroshkevich , O. Verkhodanov

We prepare real-life Cosmic Microwave Background (CMB) lensing extraction with the forthcoming Planck satellite data, by studying two systematic effects related to the foregrounds contamination: the impact of foreground residuals after a…

宇宙学与河外天体物理 · 物理学 2009-11-12 L. Perotto , J. Bobin , S. Plaszczynski , J. -L. Starck , A. Lavabre

Over the last decade, measurements of the CMB anisotropy has spearheaded the remarkable transition of cosmology into a precision science. However, addressing the systematic effects in the increasingly sensitive, high resolution, `full' sky…

天体物理学 · 物理学 2009-03-31 Sanjit Mitra , Anand S. Sengupta , Subharthi Ray , Rajib Saha , Tarun Souradeep

It is possible to classify pixels of a smoothed cosmic microwave background (CMB) fluctuation map according to their local curvature in ``hill'', ``lake'' and ``saddle'' regions. In the Gaussian case, fractional areas occupied by pixels of…

天体物理学 · 物理学 2011-05-10 O. Doré , S. Colombi , F. R. Bouchet

We introduce a pixel space method to detect dipole modulation or hemispherical power asymmetry in the cosmic microwave background (CMB) polarization. The method relies on the use of squared total polarized flux whose ensemble average picks…

宇宙学与河外天体物理 · 物理学 2020-07-15 Shamik Ghosh , Pankaj Jain

We present a Bayesian parametric component separation method for polarised microwave sky maps. We solve jointly for the primary cosmic microwave background (CMB) signal and the main Galactic polarised foreground components. For the latter,…

宇宙学与河外天体物理 · 物理学 2022-10-12 Roger de Belsunce , Steven Gratton , George Efstathiou

Multi-frequency observations are needed to separate the CMB from foregrounds and accurately extract cosmological information from the data. The Analytical Blind Separation (ABS) method is dedicated to extracting the CMB power spectrum from…

宇宙学与河外天体物理 · 物理学 2021-03-22 Larissa Santos , Jian Yao , Le Zhang , Shamik Ghosh , Pengjie Zhang , Wen Zhao , Thyrso Villela , Jiming Chen , Jacques Delabrouille