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I describe a method to estimate response matrices of Cosmic Microwave Background (CMB) lensing power spectra estimators to the true sky power under realistic conditions. Applicable to all lensing reconstruction pipelines based on quadratic…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-08 Julien Carron

To study the early Universe, it is essential to estimate cosmological parameters with high accuracy, which depends on the optimal reconstruction of Cosmic Microwave Background (CMB) maps and the measurement of their power spectrum. In this…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-10 Belén Costanza , Claudia G. Scóccola , Matías Zaldarriaga

We present the implementation of a fast estimator for the full dark matter bispectrum of a three-dimensional particle distribution relying on a separable modal expansion of the bispectrum. The computational cost of accurate bispectrum…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 M. M. Schmittfull , D. M. Regan , E. P. S. Shellard

High-dimensional matrix regression has been studied in various aspects, such as statistical properties, computational efficiency and application to specific instances including multivariate regression, system identification and matrix…

Statistics Theory · Mathematics 2024-03-06 Xin Li , Dongya Wu

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…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-19 Toshiya Namikawa , Blake D. Sherwin

In order to best improve constraints on cosmological parameters and on models of modified gravity using current and future galaxy surveys it is necessary maximally exploit the available data. As redshift-space distortions mean statistical…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Donough Regan

In unconstrained maximum a posteriori (MAP) and maximum likelihood estimation, the inverse of minus the merit-function Hessian matrix is an approximation of the estimate covariance matrix. In the Bayesian context of MAP estimation, it is…

Methodology · Statistics 2020-03-17 Dimas Abreu Archanjo Dutra

Many inverse problems include nuisance parameters which, while not of direct interest, are required to recover primary parameters. Structure present in these problems allows efficient optimization strategies - a well known example is…

Numerical Analysis · Mathematics 2015-06-05 Aleksandr Y. Aravkin , Tristan van Leeuwen

We test anisotropic dark energy models with the 7-year WMAP temperature observations data. In the presence of imperfect sources, due to large-scale gradients or anisotropies in the dark energy field, the CMB sky will be distorted…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-08 Magnus J. Axelsson , Frode K. Hansen , Tomi Koivisto , David F. Mota

I develop a method for assessing the ability of an instrument, coupled with an observing strategy, to measure the angular power spectrum of the cosmic microwave background (CMB). It allows for efficient calculation of expected parameter…

Astrophysics · Physics 2009-10-28 Lloyd Knox

The asymptotic variance of the maximum likelihood estimate is proved to decrease when the maximization is restricted to a subspace that contains the true parameter value. Maximum likelihood estimation allows a systematic fitting of…

Statistics Theory · Mathematics 2018-01-31 Marie Turčičová , Jan Mandel , Kryštof Eben

A Quadratic Maximum Likelihood (QML) estimator is applied to the WMAP 5 year low resolution maps to compute the CMB angular power spectra at large scales for both temperature and polarization. Estimates and error bars for the six angular…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-02 A. Gruppuso , A. De Rosa , P. Cabella , F. Paci , F. Finelli , P. Natoli , G. de Gasperis , N. Mandolesi

Gravitational lensing of the CMB is a valuable cosmological signal that correlates to tracers of large-scale structure and acts as a important source of confusion for primordial $B$-mode polarization. State-of-the-art lensing reconstruction…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-05 Julien Carron , Antony Lewis

We apply state-of-the art data analysis methods to a number of fictitious CMB mapping experiments, including 1/f noise, distilling the cosmological information from time-ordered data to maps to power spectrum estimates, and find that in all…

Astrophysics · Physics 2008-11-26 Max Tegmark

Higher-order spectra (or polyspectra), defined as the Fourier Transform of a stationary process' autocumulants, are useful in the analysis of nonlinear and non Gaussian processes. Polyspectral means are weighted averages over Fourier…

Statistics Theory · Mathematics 2024-10-23 Dhrubajyoti Ghosh , Tucker McElroy , Soumendra Lahiri

Inflation gives rise to a nearly scale-invariant spectrum of tensor perturbations (gravitational waves), their contribution to the Cosmic Background Radiation (CBR) anisotropy depends upon the present cosmological parameters as well as…

Astrophysics · Physics 2014-10-13 Michael S. Turner , Yun Wang

For those angular multipoles where cosmic variance is an issue, non-Gaussianities in the Cosmic Microwave Background (CMB) anisotropies will be hard to detect. Here, we construct explicitly the best unbiased estimator for the CMB angular…

Astrophysics · Physics 2007-05-23 Alejandro Gangui

We propose a new internal linear combination (ILC) method in the pixel space, applicable on large angular scales of the sky, to estimate a foreground minimized Cosmic Microwave Background (CMB) temperature anisotropy map by incorporating…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Vipin Sudevan , Rajib Saha

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…

Astrophysics · Physics 2010-11-17 Antony Lewis

Breast cancer is the most common invasive cancer in women. Besides the primary B-mode ultrasound screening, sonographers have explored the inclusion of Doppler, strain and shear-wave elasticity imaging to advance the diagnosis. However,…

Image and Video Processing · Electrical Eng. & Systems 2020-08-11 Wang Jian , Miao Juzheng , Yang Xin , Li Rui , Zhou Guangquan , Huang Yuhao , Lin Zehui , Xue Wufeng , Jia Xiaohong , Zhou Jianqiao , Huang Ruobing , Ni Dong
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