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We propose fast, exact and efficient algorithms for the convolution of two arbitrary functions on the sphere which speed up computations by a factor \order{\sqrt{N}} compared to present methods where $N$ is the number of pixels. No…

天体物理学 · 物理学 2009-10-31 Benjamin D. Wandelt , Krzysztof M. Gorski

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

We use the large cosmological Millennium Simulation (MS) to construct the first all-sky maps of the lensing potential and the deflection angle, aiming at gravitational lensing of the CMB, with the goal of properly including small-scale…

Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the…

宇宙学与河外天体物理 · 物理学 2025-07-22 Mariona Giner Mascarell , Emory F. Bunn

Szapudi et al (2001) introduced the method of estimating angular power spectrum of the CMB sky via heuristically weighted correlation functions. Part of the new technique is that all (co)variances are evaluated by massive Monte Carlo…

天体物理学 · 物理学 2007-05-23 I. Szapudi , S. Prunet , S. Colombi

Upcoming ground-based cosmic microwave background experiments will provide CMB maps with high sensitivity and resolution that can be used for high fidelity lensing reconstruction. However, the sky coverage will be incomplete and the noise…

宇宙学与河外天体物理 · 物理学 2019-12-11 Mark Mirmelstein , Julien Carron , Antony Lewis

The spherical harmonic transform is a powerful tool in the analysis of spherical data sets, such as the cosmic microwave background data. In this work, we present a new scheme for the spherical harmonic transforms that supports both CPU and…

天体物理仪器与方法 · 物理学 2022-11-18 Chi Tian , Siyu Li , Hao Liu

We present a novel method for generation of sets of the Cosmic Microwave Background (CMB) anisotropy maps, which reproduces the $\Delta \l=2$ correlations associated with Alfv\'en turbulence. The method is based on the non-linear…

天体物理学 · 物理学 2008-09-17 Pavel Naselsky , Jaiseung Kim

Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are…

天体物理学 · 物理学 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

Based on realistic simulations, we propose an hybrid method to reconstruct the lensing potential power spectrum, directly on PLANCK-like CMB frequency maps. It implies using a large galactic mask and dealing with a strong inhomogeneous…

宇宙学与河外天体物理 · 物理学 2015-03-20 S. Plaszczynski , A. Lavabre , L. Perotto , J. -L. Starck

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

天体物理学 · 物理学 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

We investigate various pixelizations of the sky which allow for fast spherical transforms, for implementation in full sky CMB experiments such as Planck and MAP. We study the effect of varying pixel shape and area on the extraction of the…

天体物理学 · 物理学 2016-08-30 Robert G. Crittenden , Neil G. Turok

The presence of astrophysical emissions between the last scattering surface and our vantage point requires us to apply a foreground mask on CMB sky map, leading to large cut around the Galactic equator and numerous holes. Since many CMB…

宇宙学与河外天体物理 · 物理学 2012-04-17 Jaiseung Kim , Pavel Naselsky , Nazzareno Mandolesi

Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-C_l…

宇宙学与河外天体物理 · 物理学 2014-03-26 H. F. Gruetjen , E. P. S. Shellard

In order to extract cosmological information from observations of the millimeter and submillimeter sky, foreground components must first be removed to produce an estimate of the cosmic microwave background (CMB). We developed a…

宇宙学与河外天体物理 · 物理学 2020-11-10 Matthew A. Petroff , Graeme E. Addison , Charles L. Bennett , Janet L. Weiland

We present a method for beam deconvolution for cosmic microwave background (CMB) anisotropy measurements. The code takes as input the time-ordered data, along with the corresponding detector pointings and known beam shapes, and produces as…

天体物理仪器与方法 · 物理学 2015-06-11 Elina Keihänen , Martin Reinecke

We describe a fast and accurate method to perform the convolution of a sky map with a general asymmetric main beam along any given scanning strategy. The method is based on the decomposition of the beam as a sum of circular functions, here…

天体物理学 · 物理学 2009-11-10 M. Tristram , J. -C. Hamilton , J. F. Macias-Perez , C. Renault

Recent analyses of the WMAP data seem to indicate the possible presence of large-angle anisotropy in the Universe. If confirmed, these can have important consequences for our understanding of the Universe. A number of attempts have recently…

天体物理学 · 物理学 2009-06-23 A. Bernui , B. Mota , M. J. Reboucas , R. Tavakol

We present a general method for accelerating by more than an order of magnitude the convolution of pixelated functions on the sphere with a radially-symmetric kernel. Our method splits the kernel into a compact real-space component and a…

宇宙学与河外天体物理 · 物理学 2015-03-31 P. M. Sutter , Benjamin D. Wandelt , Franz Elsner

We present a parallel implementation of a map-making algorithm for CMB anisotropy experiments which is both fast and efficient. We show for the first time a Maximum Likelihood, minimum variance map obtained by processing the entire data…

天体物理学 · 物理学 2014-10-13 P. Natoli , G. de Gasperis , C. Gheller , N. Vittorio
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