中文
相关论文

相关论文: CMB power spectrum estimation and map reconstructi…

200 篇论文

We report an improved technique for diffuse foreground minimization from Cosmic Microwave Background (CMB) maps using a new multi-phase iterative internal-linear-combination (ILC) approach in harmonic space. The new procedure consists of…

宇宙学与河外天体物理 · 物理学 2017-09-18 Vipin Sudevan , Pavan K. Aluri , Sarvesh Kumar Yadav , Rajib Saha , Tarun Souradeep

We propose a Bayesian expectation-maximization (EM) algorithm for reconstructing Markov-tree sparse signals via belief propagation. The measurements follow an underdetermined linear model where the regression-coefficient vector is the sum…

机器学习 · 统计学 2013-08-27 Zhao Song , Aleksandar Dogandzic

The Cosmic Microwave Background Radiation (CMBR) holds information about almost all the fundamental cosmological parameters, and by performing a likelihood analysis of high precision CMBR fluctuation data, these parameters can be inferred.…

天体物理学 · 物理学 2009-10-31 Steen Hannestad

From CMB polarization data alone we reconstruct the CMB lensing power spectrum, comparable in overall constraining power to previous temperature-based reconstructions, and an unlensed E-mode power spectrum. The observations, taken in 2019…

Observations of the Cosmic Microwave Background (CMB) provide increasingly accurate information about the structure of the Universe at the recombination epoch. Most of this information is encoded in the angular power spectrum of the CMB.…

天体物理学 · 物理学 2011-08-01 G. Faÿ , F. Guilloux , M. Betoule , J. -F. Cardoso , J. Delabrouille , M. Le Jeune

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

In recent years the goal of estimating different cosmological parameters precisely has set new challenges in the effort to accurately measure the angular power spectrum of CMB. This has required removal of foreground contamination as well…

天体物理学 · 物理学 2008-11-26 Rajib Saha , Simon Prunet , Pankaj Jain , Tarun Souradeep

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…

This paper presents a mutual coupling based calibration method for time-division-duplex massive MIMO systems, which enables downlink precoding based on uplink channel estimates. The entire calibration procedure is carried out solely at the…

信息论 · 计算机科学 2017-02-22 Joao Vieira , Fredrik Rusek , Ove Edfors , Steffen Malkowsky , Liang Liu , Fredrik Tufvesson

We propose a power filter Gp for linear reconstruction of the CMB signal from observational maps. This Gp filter preserves the power spectrum of the CMB signal in contrast to the Wiener filter which diminishes the power spectrum of the…

天体物理学 · 物理学 2016-08-16 D. Novikov , P. Naselsky , H. E. Jorgensen , P. R. Christensen , I. Novikov , H. U. Norgaard-Nielsen

A new method for removing point radio sources and other non-Gaussian noise is proposed as a means of improving the accuracy of estimates of the angular power spectrum of the cosmic microwave background (CMB). The main idea of the method is…

天体物理学 · 物理学 2009-11-13 Anisa T. Bajkova

We report a measurement of the E-mode polarization power spectrum of the cosmic microwave background (CMB) using 150 GHz data taken from July 2014 to December 2016 with the POLARBEAR experiment. We reach an effective polarization map noise…

The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has…

天体物理学 · 物理学 2011-04-11 Tarun Souradeep , Rajib Saha , Pankaj Jain

Expectation-Maximization (EM) algorithm is a widely used iterative algorithm for computing maximum likelihood estimate when dealing with Gaussian Mixture Model (GMM). When the sample size is smaller than the data dimension, this could lead…

机器学习 · 统计学 2023-07-06 Pierre Houdouin , Matthieu Jonkcheere , Frederic Pascal

In this study, we apply the Analytical method of Blind Separation (ABS) of the cosmic microwave background (CMB) from foregrounds to estimate the CMB temperature power spectrum from multi-frequency microwave maps. We test the robustness of…

宇宙学与河外天体物理 · 物理学 2018-12-21 Jian Yao , Le Zhang , Yuxi Zhao , Pengjie Zhang , Larissa Santos , Jun Zhang

One of the main obstacles for extracting the Cosmic Microwave Background (CMB) from mm/submm observations is the pollution from the main Galactic components: synchrotron, free-free and thermal dust emission. The feasibility of using simple…

宇宙学与河外天体物理 · 物理学 2016-07-20 H. U. Nørgaard-Nielsen

A maximum-likelihood method is presented for estimating the power spectrum of anisotropies in the cosmic microwave background (CMB) from interferometer observations. The method calculates flat band-power estimates in separate bins in…

天体物理学 · 物理学 2009-11-07 M. P. Hobson , Klaus Maisinger

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

Unprecedentedly precise cosmic microwave background (CMB) data are expected from ongoing and near-future CMB Stage-III and IV surveys, which will yield reconstructed CMB lensing maps with effective resolution approaching several arcminutes.…

宇宙学与河外天体物理 · 物理学 2016-11-09 Jia Liu , J. Colin Hill , Blake D. Sherwin , Andrea Petri , Vanessa Böhm , Zoltán Haiman

We present an augmented version of our dual messenger algorithm for spin field reconstruction on the sphere, while accounting for highly non-trivial and realistic noise models such as modulated correlated noise. We also describe an…

宇宙学与河外天体物理 · 物理学 2019-10-01 Doogesh Kodi Ramanah , Guilhem Lavaux , Benjamin D. Wandelt