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相关论文: Power spectrum estimation from high-resolution map…

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A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables the extraction of useful information from…

宇宙学与河外天体物理 · 物理学 2013-10-08 Fergus Simpson , J. Berian James , Alan F. Heavens , Catherine Heymans

A well-tested and validated Gibbs sampling code, that performs component separation and CMB power spectrum estimation, was applied to the {\it WMAP} 5-yr data. Using a simple model consisting of CMB, noise, monopoles and dipoles, a ``per…

宇宙学与河外天体物理 · 物理学 2009-11-05 C. Dickinson , H. K. Eriksen , A. J. Banday , J. B. Jewell , K. M. Gorski , G. Huey , C. R. Lawrence , I. J. O'Dwyer , B. D. Wandelt

We extend to large scales a method proposed in previous work that reconstructs non-parametrically the primordial power spectrum from cosmic microwave background data at high resolution. The improvement is necessary to account for the…

天体物理学 · 物理学 2009-11-13 Domenico Tocchini-Valentini , Yehuda Hoffman , Joseph Silk

We develop two methods for estimating the power spectrum, C_l, of the cosmic microwave background (CMB) from data and apply them to the COBE/DMR and Saskatoon datasets. One method involves a direct evaluation of the likelihood function, and…

天体物理学 · 物理学 2009-10-30 J. R. Bond , A. H. Jaffe , L. Knox

The WMAP 7-year temperature maps have been re-analized to extract a CMB map and CMB power spectrum with reduced contamination by astrophysical foregrounds and noise. The method used is based on linear combinations of WMAP data and…

宇宙学与河外天体物理 · 物理学 2015-05-28 Soumen Basak , Jacques Delabrouille

We use a Quadratic Maximum Likelihood (QML) method to estimate the angular power spectrum of the cross-correlation between cosmic microwave background and large scale structure maps as well as their individual auto-spectra. We describe our…

宇宙学与河外天体物理 · 物理学 2015-06-04 F. Schiavon , F. Finelli , A. Gruppuso , A. Marcos-Caballero , P. Vielva , R. G. Crittenden , R. B. Barreiro , E. Martinez-Gonzalez

This paper studies a spectrum estimation method for the case that the samples are obtained at a rate lower than the Nyquist rate. The method is referred to as the correlogram for undersampled data. The algorithm partitions the spectrum into…

信息论 · 计算机科学 2018-02-07 Mahdi Shaghaghi , Sergiy A. Vorobyov

For systems and devices, such as cognitive radio and networks, that need to be aware of available frequency bands, spectrum sensing has an important role. A major challenge in this area is the requirement of a high sampling rate in the…

信息论 · 计算机科学 2014-08-21 M. R. Avendi , K. Haghighi , A. Panahi , M. Viberg

We present new full-sky temperature maps in five frequency bands from 23 to 94 GHz, based on the first three years of the WMAP sky survey. The new maps, which are consistent with the first-year maps and more sensitive, incorporate…

We describe here an iterative method for jointly estimating the noise power spectrum from a scanning experiment's time-ordered data, together with the maximum-likelihood map. We test the robustness of this method on simulated datasets with…

天体物理学 · 物理学 2007-05-23 S. Prunet , C. B. Netterfield , E. Hivon , B. P. Crill

A central task in many applications is reasoning about processes that change over continuous time. Continuous-Time Bayesian Networks is a general compact representation language for multi-component continuous-time processes. However, exact…

人工智能 · 计算机科学 2012-06-18 Tal El-Hay , Nir Friedman , Raz Kupferman

We compute the two-, three- and four-point correlation functions from the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data, and compare these to a Monte Carlo ensemble of 5000 realizations, based on the best-fit WMAP…

天体物理学 · 物理学 2009-11-10 H. K. Eriksen , A. J. Banday , K. M. Gorski , P. B. Lilje

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

天体物理学 · 物理学 2009-10-07 Max Tegmark

We revisit the problem of exact CMB likelihood and power spectrum estimation with the goal of minimizing computational cost through linear compression. This idea was originally proposed for CMB purposes by Tegmark et al.\ (1997), and here…

天体物理仪器与方法 · 物理学 2015-11-18 E. Gjerløw , L. P. L. Colombo , H. K. Eriksen , K. M. Górski , A. Gruppuso , J. B. Jewell , S. Plaszczynski , I. K. Wehus

Fast robust methods for calculating likelihoods from CMB observations on small scales generally rely on approximations based on a set of power spectrum estimators and their covariances. We investigate the optimality of these approximation,…

宇宙学与河外天体物理 · 物理学 2009-11-06 Samira Hamimeche , Antony Lewis

The power spectrum of cosmic microwave background (CMB) lensing will be measured to sub-percent precision with upcoming surveys, enabling tight constraints on the sum of neutrino masses and other cosmological parameters. Measuring the…

宇宙学与河外天体物理 · 物理学 2021-11-18 Mathew S. Madhavacheril , Kendrick M. Smith , Blake D. Sherwin , Sigurd Naess

We develop optimised estimators of two sorts of power spectra for fields defined on the sky, in the presence of partial sky coverage. The first is the cross-power spectrum of two fields on the sky; the second is the skew spectrum of three…

宇宙学与河外天体物理 · 物理学 2015-05-13 Dipak Munshi , Patrick Valageas , Asantha Cooray , Alan Heavens

A new method for estimating the power spectrum $C_l$ from cosmic microwave background (CMB) maps was recently presented by the author and applied to the 2 year COBE data. It was found that the spectral resolution $\Delta l$ for COBE could…

天体物理学 · 物理学 2016-08-30 Max Tegmark

Foreground removal remains an ongoing challenge in radio cosmology, and increasingly sensitive experiments necessitate more robust analysis techniques. In this work, we model simulated data from a single-dish intensity mapping experiment,…

天体物理仪器与方法 · 物理学 2026-04-30 Geoff G. Murphy , Philip Bull , Mario G. Santos , Zheng Zhang , Steven Cunnington

We consider a search for the anisotropic stochastic gravitational-wave background (SGWB) that decomposes the sky map into its spherical harmonics components in order to obtain estimators of the angular power spectrum. Such a search often…

广义相对论与量子宇宙学 · 物理学 2026-04-21 Erik Floden , Alex Granados , Vuk Mandic