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A crucial problem for partial sky analysis of CMB polarization is the $E$-$B$ leakage problem. Such leakage arises from the presence of `ambiguous' modes that satisfy properties of both $E$ and $B$ modes. Solving this problem is critical…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Shamik Ghosh , Jacques Delabrouille , Wen Zhao , Larissa Santos

We describe a novel method for the application of Convolutional Neural Networks (CNNs) to fields defined on the sphere, using the HEALPix tessellation scheme. Specifically, We have developed a pixel-based approach to implement convolutional…

Instrumentation and Methods for Astrophysics · Physics 2019-08-21 Nicoletta Krachmalnicoff , Maurizio Tomasi

This paper provides full sky maps of foreground emission in all WMAP channels, with very low residual contamination from the Cosmic Microwave Background (CMB) anisotropies and controlled level of instrumental noise. Foreground maps are…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-25 Tuhin Ghosh , Jacques Delabrouille , Mathieu Remazeilles , Jean-Francois Cardoso , Tarun Souradeep

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

In this paper we estimate diffuse foreground minimized Cosmic Microwave Background (CMB) Stokes Q and U polarization maps based upon the fundamental concept of Gaussian nature of CMB and strong non-Gaussian nature of astrophysical polarized…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-10 Ujjal Purkayastha , Rajib Saha

We present coincident observations of the Cosmic Microwave Background (CMB) from the Very Small Array (VSA) and Cosmic Background Imager (CBI) telescopes. The consistency of the full datasets is tested in the map plane and the Fourier…

We provide computationally convenient expressions for all marginal distributions of the polarization CMB power spectrum distribution P(C_l|sigma_l), where C_l = {C_l^TT, C_l^TE, C_l^EE, C_l^BB} denotes the set of ensemble averaged…

Astrophysics · Physics 2009-01-13 Hans Kristian Eriksen , Ingunn Kathrine Wehus

The B modes generated by the lensing of CMB polarization are a primary target for the upcoming generation of experiments and can potentially constrain quantities such as the neutrino mass and dark energy equation of state. The net sample…

Astrophysics · Physics 2011-05-12 Kendrick M. Smith , Wayne Hu , Manoj Kaplinghat

The Planck satellite, along with several ground based telescopes, have mapped the cosmic microwave background (CMB) at sufficient resolution and signal-to-noise so as to allow a detection of the subtle distortions due to the gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 Ethan Anderes , Benjamin Wandelt , Guilhem Lavaux

In this work we present a Neural Network (NN) algorithm for the identification of the appropriate parametrization of diffuse polarized Galactic emissions in the context of Cosmic Microwave Background (CMB) $B$-mode multi-frequency…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 Farida Farsian , Nicoletta Krachmalnicoff , Carlo Baccigalupi

Noise maps from CMB experiments are generally statistically anisotropic, due to scanning strategies, atmospheric conditions, or instrumental effects. Any mis-modeling of this complex noise can bias the reconstruction of the lensing…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-03 Louis Legrand , Blake Sherwin , Anthony Challinor , Julien Carron , Gerrit S. Farren

In this article we present a formalism to incorporate the partial-sky maps to the Gibbs ILC algorithm to estimate the joint posterior density of the Cosmic Microwave Background (CMB) signal and the theoretical CMB angular power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Vipin Sudevan , Ujjal Purkayastha , Rajib Saha

We propose an efficient Bayesian MCMC algorithm for estimating cosmological parameters from CMB data without use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-29 Benjamin Racine , Jeffrey B. Jewell , Hans Kristian K. Eriksen , Ingunn K. Wehus

Over the past decade, the gravitational lensing of the Cosmic Microwave Background (CMB) has become a powerful tool for probing the matter distribution in the Universe. The standard technique used to reconstruct the CMB lensing signal…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-02 Boryana Hadzhiyska , Blake D. Sherwin , Mathew Madhavacheril , Simone Ferraro

The next generation of CMB experiments can measure cosmological parameters with unprecedented accuracy - in principle. To achieve this in practice when faced with such gigantic data sets, elaborate data analysis methods are needed to make…

Astrophysics · Physics 2009-10-28 Max Tegmark

One of the main obstacles for extracting the cosmic microwave background (CMB) signal from observations in the mm/sub-mm range is the foreground contamination by emission from Galactic component: mainly synchrotron, free-free, and thermal…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-07 H. U. Nørgaard-Nielsen

Minimum Bayes-Risk (MBR) decoding is shown to be a powerful alternative to beam search decoding for a wide range of text generation tasks. However, MBR requires a huge amount of time for inference to compute the MBR objective, which makes…

Artificial Intelligence · Computer Science 2024-06-13 Yuu Jinnai , Kaito Ariu

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

We present a parallel implementation of a map-making algorithm for CMB anisotropy experiments which is both fast and efficient. We show for the first time a Maximum Likelihood, minimum variance map obtained by processing the entire data…

Astrophysics · Physics 2014-10-13 P. Natoli , G. de Gasperis , C. Gheller , N. Vittorio

One of the key steps in Cosmic Microwave Background (CMB) data analysis is component separation to recover the CMB signal from multi-frequency observations contaminated by foreground emissions. Needlet Internal Linear Combination (NILC) is…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Debabrata Adak