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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 present a new method for fast computation of the realization-dependent bias, a major computational bottleneck in measurements of the cosmic microwave background (CMB) lensing power spectrum. The method accelerates the bias calculation by…

宇宙学与河外天体物理 · 物理学 2026-05-19 Toshiya Namikawa , Blake D. Sherwin

Fundamental information about the Universe is encoded in anisotropies of the Cosmic Microwave Background (CMB) radiation. To make full use of this information, an experiment must image the entire sky with the angular resolution,…

A flexible maximum-entropy component separation algorithm is presented that accommodates anisotropic noise, incomplete sky-coverage and uncertainties in the spectral parameters of foregrounds. The capabilities of the method are determined…

天体物理学 · 物理学 2009-11-07 R. B. Barreiro , M. P. Hobson , A. J. Banday , A. N. Lasenby , V. Stolyarov , P. Vielva , K. M. Gorski

We discuss an approach to the component separation of microwave, multi-frequency sky maps as those typically produced from Cosmic Microwave Background (CMB) Anisotropy data sets. The algorithm is based on the two step, parametric,…

天体物理学 · 物理学 2009-06-23 R. Stompor , S. Leach , F. Stivoli , C. Baccigalupi

A fundamental assumption in cosmology is that of statistical isotropy - that the universe, on average, looks the same in every direction in the sky. Statistical isotropy has recently been tested stringently using Cosmic Microwave Background…

宇宙学与河外天体物理 · 物理学 2011-09-14 Caroline Zunckel , Dragan Huterer , Glenn D. Starkman

Accurate measurements of the Cosmic Microwave Background (CMB) anisotropy call for high precision and reliability of the in-flight calibration. For extended surveys the CMB dipole provides an excellent calibration source at frequencies…

天体物理学 · 物理学 2009-11-10 B. Cappellini , D. Maino , G. Albetti , P. Platania , R. Paladini , A. Mennella , M. Bersanelli

Reliable extraction of cosmological information from observed cosmic microwave background (CMB) maps may require removal of strongly foreground contaminated regions from the analysis. In this article, we employ an artificial neural network…

宇宙学与河外天体物理 · 物理学 2023-03-13 Srikanta Pal , Pallav Chanda , Rajib Saha

Large scale structure deflects cosmic microwave background (CMB) photons. Since large angular scales in the large scale structure contribute significantly to the gravitational lensing effect, a realistic simulation of CMB lensing requires a…

天体物理学 · 物理学 2009-11-13 Sudeep Das , Paul Bode

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…

Broadband time-ordered data obtained from telescopes with a wavelength-dependent, asymmetric beam pattern can be used to extract maps at multiple wavelengths from a single scan. This technique is especially useful when collecting data on…

天体物理仪器与方法 · 物理学 2023-06-06 Brianna Cantrall , Solomon Quinn , Emory F. Bunn

The CMB maps obtained by observations always possess domains which have to be masked due to severe uncertainties with respect to the genuine CMB signal. Cosmological analyses ideally use full CMB maps in order to get e.g. the angular power…

宇宙学与河外天体物理 · 物理学 2015-05-19 R. Aurich , S. Lustig

Weak lensing of CMB anisotropies and polarization for the power spectra and higher order statistics can be handled directly in harmonic-space without recourse to real-space correlation functions. For the power spectra, this approach not…

天体物理学 · 物理学 2009-10-31 Wayne Hu

Statistical isotropy (SI) is one of the fundamental assumptions made in cosmological model building. This assumption is now being rigorously tested using the almost full sky measurements of the CMB anisotropies. A major hurdle in any such…

宇宙学与河外天体物理 · 物理学 2015-11-04 Pavan K. Aluri , Nidhi Pant , Aditya Rotti , Tarun Souradeep

We describe a accurate and fast pixel-based statistical method to interpolate fields of arbitrary spin on the sphere. We call this method Fast and Lean Interpolation on the Sphere (FLINTS). The method predicts the optimal interpolated…

宇宙学与河外天体物理 · 物理学 2010-10-21 Guilhem Lavaux , Benjamin D. Wandelt

We propose a factorizability ansatz for angular bispectra which permits fast algorithms for forecasting, analysis, and simulation, yet is general enough to encompass many interesting CMB bispectra. We describe a suite of general algorithms…

天体物理学 · 物理学 2011-11-09 Kendrick M. Smith , Matias Zaldarriaga

A number of experiments for measuring anisotropies of the Cosmic Microwave Background use scanning strategies in which temperature fluctuations are measured along circular scans on the sky. It is possible, from a large number of such…

天体物理学 · 物理学 2009-10-30 J. Delabrouille , K. M. Górski , E. Hivon

Precise measurement of the angular power spectrum of the Cosmic Microwave Background (CMB) temperature and polarization anisotropy can tightly constrain many cosmological models and parameters. However, accurate measurements can only be…

宇宙学与河外天体物理 · 物理学 2015-03-17 S. Mitra , G. Rocha , K. M. Górski , K. M. Huffenberger , H. K. Eriksen , M. A. J. Ashdown , C. R. Lawrence

We have developed a fast, accurate and generally applicable method for inferring the power spectrum and its uncertainties from maps of the cosmic microwave background (CMB) in the presence of inhomogeneous and correlated noise. For maps…

天体物理学 · 物理学 2014-10-13 O. Doré , L. Knox , A. Peel

We develop computationally rapid methods to compute the window function for a cosmic microwave background anisotropy experiment with a non-circular beam which scans over large angles on the sky. To concretely illustrate these methods we…

天体物理学 · 物理学 2009-11-06 Tarun Souradeep , Bharat Ratra