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Galactic foregrounds are the main obstacle to observations of the cosmic microwave background (CMB) $B$-mode polarization. In addition to obscuring the inflationary $B$-mode signal by several orders of magnitude, Galactic foregrounds have…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Mathieu Remazeilles , Aditya Rotti , Jens Chluba

We estimate Cosmic Microwave Background (CMB) polarisation power spectra, and temperature-polarisation cross-spectra, from the 9-year data of the Wilkinson Microwave Anisotropy Probe (WMAP). Foreground cleaning is implemented using minimum…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-02 Soumen Basak , Jacques Delabrouille

The Planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. The goal of this paper is to compare proposed methods…

We propose a solution to the CMB component separation problem based on standard parameter estimation techniques. We assume a parametric spectral model for each signal component, and fit the corresponding parameters pixel by pixel in a…

Today, image denoising by thresholding of wavelet coefficients is a commonly used tool for 2D image enhancement. Since the data product of spectroscopic imaging surveys has two spatial and one spectral dimension, the techniques for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Lars Flöer , Benjamin Winkel

The polarization of the Cosmic Microwave Background (CMB)is a powerful observational tool at hand for modern cosmology. It allows to break the degeneracy of fundamental cosmological parameters one cannot obtain using only anisotropy data…

Astrophysics · Physics 2009-11-07 M. V. Sazhin , G. Sironi , O. S. Khovanskaya

An algorithm is proposed for denoising the signal induced by cosmic strings in the cosmic microwave background (CMB). A Bayesian approach is taken, based on modeling the string signal in the wavelet domain with generalized Gaussian…

Astrophysics · Physics 2009-11-16 D. K. Hammond , Y. Wiaux , P. Vandergheynst

The internal linear combination (ILC) method is a popular approach for constructing component-separated maps in cosmic microwave background (CMB) analyses. It optimally combines observed maps at different frequencies to produce an unbiased…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Kristen M. Surrao , J. Colin Hill

Cosmic microwave background (CMB) experiments that constrain the tensor-to-scalar ratio $r$ are now approaching the sensitivity at which delensing---removing the $B$ modes induced by the gravitational lensing of large-scale structure---is…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-23 Kirit S. Karkare

Natural signals and images are well-known to be approximately sparse in transform domains such as Wavelets and DCT. This property has been heavily exploited in various applications in image processing and medical imaging. Compressed sensing…

Machine Learning · Computer Science 2015-10-26 Saiprasad Ravishankar , Yoram Bresler

We discuss Spherical Needlets and their properties. Needlets are a form of spherical wavelets which do not rely on any kind of tangent plane approximation and enjoy good localization properties in both pixel and harmonic space; moreover…

Multilevel Image thresholding is an important preprocessing algorithm in computer vision applications nowadays. Since most common thresholding methods take the desired count of thresholds as input by the user, thresholding methods that…

Computer Vision and Pattern Recognition · Computer Science 2026-05-27 Eslam Hegazy , Mohamed Gabr

Sampling and quantization are standard practices in signal and image processing, but a theoretical understanding of their impact is incomplete. We consider discrete image registration when the underlying function is a one-dimensional…

Computer Vision and Pattern Recognition · Computer Science 2024-10-28 Serap A. Savari

The delensing of cosmic microwave background (CMB) maps will be increasingly valuable for extracting as much information as possible from future CMB surveys. Delensing provides many general benefits, including sharpening of the acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-20 Cynthia Trendafilova , Selim C. Hotinli , Joel Meyers

Delensing is an increasingly important technique to reverse the gravitational lensing of the cosmic microwave background (CMB) and thus reveal primordial signals the lensing may obscure. We present a first demonstration of delensing on…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-12 Patricia Larsen , Anthony Challinor , Blake D. Sherwin , Daisy Mak

We evaluate the expected level of foreground contamination to the cosmic microwave background (CMB) polarised radiation, focusing on the diffuse emission from our own Galaxy. In particular, we perform a first attempt to simulate an all sky…

Astrophysics · Physics 2015-06-24 Carlo Baccigalupi

We present a blind multi-detector multi-component spectral matching method for all sky observations of the cosmic microwave background, working on the spherical harmonics basis. The method allows to estimate on a set of observation maps the…

Astrophysics · Physics 2007-05-23 G. Patanchon , H. Snoussi , J. F. Cardoso , J. Delabrouille

We propose a non-parametric method to denoise 1D stellar spectra based on wavelet shrinkage followed by adaptive Kalman thresholding. Wavelet shrinkage denoising involves applying the Discrete Wavelet Transform (DWT) to the input signal,…

Instrumentation and Methods for Astrophysics · Physics 2020-07-03 Sankalp Gilda , Zachary Slepian

Image segmentation is a fundamental step for the interpretation of Remote Sensing Images. Clustering or segmentation methods usually precede the classification task and are used as support tools for manual labeling. The most common…

Computer Vision and Pattern Recognition · Computer Science 2022-03-08 Kiran Mantripragada , Faisal Z. Qureshi

We present a study of the effect of component separation on the recovered cosmic microwave background (CMB) temperature distribution, considering Gaussian and non-Gaussian input CMB maps. First, we extract the CMB component from simulated…

Astrophysics · Physics 2009-11-10 R. B. Barreiro , E. Martinez-Gonzalez , P. Vielva , M. P. Hobson