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Related papers: Applications of Fast Convolution on the Sphere

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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…

Astrophysics · Physics 2009-10-31 Benjamin D. Wandelt , Krzysztof M. Gorski

We discuss all-sky convolution of the instrument beam with the sky signal in polarimetry experiments, such as the Planck mission which will map the temperature anisotropy and polarization of the cosmic microwave background (CMB). To account…

We describe the construction of a spherical wavelet analysis through the inverse stereographic projection of the Euclidean planar wavelet framework, introduced originally by Antoine and Vandergheynst and developed further by Wiaux et al.…

Astrophysics · Physics 2011-10-28 J. D. McEwen , M. P. Hobson , D. J. Mortlock , A. N. Lasenby

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 S. Mitra , G. Rocha , K. M. Górski , K. M. Huffenberger , H. K. Eriksen , M. A. J. Ashdown , C. R. Lawrence

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…

Astrophysics · Physics 2009-11-10 M. Tristram , J. -C. Hamilton , J. F. Macias-Perez , C. Renault

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…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

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

Instrumentation and Methods for Astrophysics · Physics 2012-11-16 P. M. Sutter , Benjamin D. Wandelt , Franz Elsner

One of the main goals of modern observational cosmology is to map the large scale structure of the Universe. A potentially powerful approach for doing this would be to exploit three-dimensional spectral maps, i.e. the specific intensity of…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-18 Roland de Putter , Gilbert P. Holder , Tzu-Ching Chang , Olivier Dore

We present a fast method for estimating the cosmic microwave background polarization power spectra using unbiased estimates of heuristically-weighted correlation functions. This extends the O(N_pix^(3/2)) method of Szapudi et al. (2001) to…

Astrophysics · Physics 2009-11-07 Gayoung Chon , Anthony Challinor , Simon Prunet , Eric Hivon , Istvan Szapudi

(Abridged) In the first part of this thesis, a general methodology for applying image deconvolution to wide-field CCD imagery. Results show that wavelet-based deconvolution can increase limiting magnitude up to 0.6 mag and improve limiting…

Astrophysics · Physics 2007-05-23 O. Fors

Next-generation centimeter to sub-millimeter telescopes require exquisite control over instrumental far-sidelobe response to accurately measure faint signals like the Cosmic Microwave Background B modes. Because existing electromagnetic…

Instrumentation and Methods for Astrophysics · Physics 2025-12-24 Oliver Jeong , Jacques Delabrouille , Michel Piat

A fast algorithm is developed for the directional correlation of scalar band-limited signals and band-limited steerable filters on the sphere. The asymptotic complexity associated to it through simple quadrature is of order O(L^5), where 2L…

Astrophysics · Physics 2011-02-11 Y. Wiaux , L. Jacques , P. Vielva , P. Vandergheynst

The Five-hundred-metre Aperture Spherical Telescope (FAST) uses adaptive spherical panels to achieve a huge collecting area for radio waves. In this paper, we try to explore the optimal parameters for the curvature radius of spherical…

Instrumentation and Methods for Astrophysics · Physics 2013-08-01 B. Dong , J. L. Han

We introduce a publicly available full-sky beam convolution code library intended to inform the design of future cosmic microwave background (CMB) instruments and help current experiments probe potential systematic effects. The code can be…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 Adriaan J. Duivenvoorden , Jon E. Gudmundsson , Alexandra S. Rahlin

This paper discusses the Cosmic Background (CB) dipoles observations in the framework of the Planck mission. Dipoles observations can be used in three ways: (i) It gives a measurement of the peculiar velocity of our Galaxy which is an…

Astrophysics · Physics 2009-11-07 M. Piat , G. Lagache , J. P. Bernard , M. Giard , J. L. Puget

Polarized light microscopy, as a contrast-enhancing technique for optically anisotropic materials, is a method well suited for the investigation of a wide variety of effects in solid-state physics, as for example birefringence in crystals…

Instrumentation and Detectors · Physics 2017-12-19 Matthias Lange , Stefan Guénon , Felix Lever , Reinhold Kleiner , Dieter Koelle

Invertible convolutions have been an essential element for building expressive normalizing flow-based generative models since their introduction in Glow. Several attempts have been made to design invertible $k \times k$ convolutions that…

Computer Vision and Pattern Recognition · Computer Science 2023-01-24 Aditya Kallappa , Sandeep Nagar , Girish Varma

We develop a sampling scheme on the sphere that permits accurate computation of the spherical harmonic transform and its inverse for signals band-limited at $L$ using only $L^2$ samples. We obtain the optimal number of samples given by the…

Information Theory · Computer Science 2014-07-25 Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

We introduce the concept of compressed convolution, a technique to convolve a given data set with a large number of non-orthogonal kernels. In typical applications our technique drastically reduces the effective number of computations. The…

Instrumentation and Methods for Astrophysics · Physics 2014-01-08 F. Elsner , B. D. Wandelt
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