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We present a simple approximation that can speed up the computation of the mode-coupling matrices, which are usually the bottleneck for computing unbiased angular power spectra, as well as their associated covariance matrices, of the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-04 Thibaut Louis , Sigurd Naess , Xavier Garrido , Anthony Challinor

We consider a linear iterative solver for large scale linearly constrained quadratic minimization problems that arise, for example, in optimization with PDEs. By a primal-dual projection (PDP) iteration, which can be interpreted and…

Optimization and Control · Mathematics 2020-12-07 Anton Schiela , Matthias Stöcklein , Martin Weiser

This paper deals with improvements to the contrast source inversion method which is widely used in microwave tomography. First, the method is reviewed and weaknesses of both the criterion form and the optimization strategy are underlined.…

Numerical Analysis · Mathematics 2009-01-30 Paul-André Barrière , Jérôme Idier , Yves Goussard , Jean-Jacques Laurin

The characterization of the dust polarization foreground to the Cosmic Microwave Background (CMB) is a necessary step towards the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate…

The aim of this project is to recover the CMB anisotropies maps in temperature and polarized intensity by means of a deep convolutional neural network (CNN) which, after appropiate training, can remove the foregrounds from Planck and…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-29 A. Quintana-Estellés , B. Ruiz-Granados , P. Ruiz-Lapuente

Long-tailed instance segmentation is a challenging task due to the extreme imbalance of training samples among classes. It causes severe biases of the head classes (with majority samples) against the tailed ones. This renders "how to…

Computer Vision and Pattern Recognition · Computer Science 2022-04-05 Yin-Yin He , Peizhen Zhang , Xiu-Shen Wei , Xiangyu Zhang , Jian Sun

Using the formalism of spin-weighted functions we present an all-sky analysis of polarization in the Cosmic Microwave Background (CMB). Linear polarization is a second-rank symmetric and traceless tensor, which can be decomposed on a sphere…

Astrophysics · Physics 2009-10-28 Matias Zaldarriaga , Uros Seljak

The Morse-Ingard equations of thermoacoustics are a system of coupled time-harmonic equations for the temperature and pressure of an excited gas. They form a critical aspect of modeling trace gas sensors. In this paper, we analyze a…

Numerical Analysis · Mathematics 2019-11-26 Peter Coogan , Robert C. Kirby

In our previous study, we introduced a machine-learning technique, namely CMBFSCNN, for the removal of foreground contamination in cosmic microwave background (CMB) polarization data. This method was successfully employed on actual…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-19 Ye-Peng Yan , Si-Yu Li , Guo-Jian Wang , Zirui Zhang , Jun-Qing Xia

The search for primordial gravitational waves is a central goal of cosmic microwave background (CMB) surveys. Isolating the characteristic $B$-mode polarization signal sourced by primordial gravitational waves is challenging for several…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Eric Guzman , Joel Meyers

AIMS: One of the most challenging and important problem of digital signal processing in Cosmology is the separation of foreground contamination from cosmic microwave background (CMB). This problem becomes even more difficult in situations,…

Astrophysics · Physics 2008-02-05 Robertio Vio , Paola Andreani

Obtaining high-sensitivity measurements of degree-scale cosmic microwave background (CMB) polarization is the most direct path to detecting primordial gravitational waves. Robustly recovering any primordial signal from the dominant…

Instrumentation and Methods for Astrophysics · Physics 2017-04-20 Stephen M. Feeney , Jon E. Gudmundsson , Hiranya V. Peiris , Licia Verde , Josquin Errard

The Cosmic Microwave Background (CMB) radiation offers a unique window into the early Universe, facilitating precise examinations of fundamental cosmological theories. However, the quest for detecting B-modes in the CMB, predicted by…

Solving systems of linear equations is a problem occuring frequently in water engineering applications. Usually the size of the problem is too large to be solved via direct factorization. One can resort to iterative approaches, in…

Machine Learning · Computer Science 2019-06-18 Johannes Sappl , Laurent Seiler , Matthias Harders , Wolfgang Rauch

We evaluate the modulation of Cosmic Microwave Background (CMB) polarization using a rapidly-rotating, half-wave plate (HWP) on the Atacama B-Mode Search (ABS). After demodulating the time-ordered-data (TOD), we find a significant reduction…

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

We extend the internal template foreground removal method by accounting for spatially varying spectral parameters such as the spectral indices of synchrotron and dust emission and the dust temperature. As the previous algorithm had to…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-04 Kiyotomo Ichiki , Hiroaki Kanai , Nobuhiko Katayama , Eiichiro Komatsu

The B-mode polarisation power spectrum in the Cosmic Microwave Background (CMB) is about four orders of magnitude fainter than the CMB temperature power spectrum. Any instrumental imperfections that couple temperature fluctuations to B-mode…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Christopher G. R. Wallis , Michael L. Brown , Richard A. Battye , Jacques Delabrouille

Markov Chain Monte Carlo (MCMC) underlies both statistical physics and combinatorial optimization, but mixes slowly near critical points and in rough landscapes. Parallel Tempering (PT) improves mixing by swapping replicas across…

Machine Learning · Computer Science 2025-09-30 Saleh Bunaiyan , Corentin Delacour , Shuvro Chowdhury , Kyle Lee , Kerem Y. Camsari

Polarization plays an important role in various time-domain astrophysics to understand the magnetic fields, geometry, and environments of spatially unresolved variable sources. In this paper we present the results of laboratory and on-sky…

Instrumentation and Methods for Astrophysics · Physics 2020-04-29 Manisha Shrestha , Iain A. Steele , Andrez S. Piascik , Helen Jermak , Robert J. Smith , Chris M. Copperwheat