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We present measurements of large-scale cosmic microwave background (CMB) E-mode polarization from the Cosmology Large Angular Scale Surveyor (CLASS) 90 GHz data. Using 115 det-yr of observations collected through 2024 with a variable-delay…

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

The B-Machine Telescope is the culmination of several years of development, construction, characterization and observation. The telescope is a departure from standard polarization chopping of correlation receivers to a half wave plate…

Instrumentation and Methods for Astrophysics · Physics 2013-11-11 Brian D. Williams

Efforts are being made to observe the 21-cm signal from the 'cosmic dawn' using sky-averaged observations with individual radio dipoles. In this paper, we develop a model of the observations accounting for the 21-cm signal, foregrounds, and…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-26 Geraint J. A. Harker , Jonathan R. Pritchard , Jack O. Burns , Judd D. Bowman

We quantify the level of polarization of the atmosphere due to Zeeman splitting of oxygen in the Earth's magnetic field and compare it to the level of polarization expected from the polarization of the cosmic microwave background radiation.…

Astrophysics · Physics 2015-06-24 Shaul Hanany , Philip Rosenkranz

We present a novel method for Cosmic Microwave Background (CMB) foreground removal based on deep learning techniques. This method employs a Transformer model, referred to as \texttt{TCMB}, which is specifically designed to effectively…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-09 Ye-Peng Yan , Si-Yu Li , Yang Liu , Jun-Qing Xia , Hong Li

We investigate the E/B decomposition of CMB polarization on a masked sky. In real space, operators of E and B mode decomposition involve only differentials of CMB polarization. We may, therefore in principle, perform a clean E/B…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-10 Jaiseung Kim

Studies of the cosmic dark ages ($30 \lesssim z \lesssim 150$) using the highly redshifted 21 cm line of neutral hydrogen offer unparalleled amounts of cosmological information, and recent years have seen the refinement of concepts for such…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-01 Jonathan C. Pober , Willow Smith

Deep cosmic microwave background polarization experiments allow a very precise internal reconstruction of the gravitational lensing signal in pricinple. For this aim, likelihood-based or Bayesian methods are typically necessary, where very…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-25 Martin Reinecke , Sebastian Belkner , Julien Carron

The full sky cosmic microwave background polarization field can be decomposed into `electric' and `magnetic' components. Working in harmonic space we construct magnetic variables that can be measured from observations over only a portion of…

Astrophysics · Physics 2007-05-23 Antony Lewis , Anthony Challinor , Neil Turok

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

Measuring the imprint of primordial gravitational waves in the cosmic microwave background (CMB) polarisation field is one of the main goals in modern cosmology. However, the so called $B$-mode polarisation can be generated by different…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-22 Larissa Santos , Wen Zhao

Precise polarisation measurements of the cosmic microwave background (CMB) require accurate knowledge of the instrument orientation relative to the sky frame used to define the cosmological Stokes parameters. Suitable celestial calibration…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-09 M. H. Abitbol , J. C. Hill , B. R. Johnson

A primordial degree of circular polarization of the Cosmic Microwave Background is not observationally excluded. The hypothesis of primordial dichroism can be quantitatively falsified if the plasma is magnetized prior to photon decoupling…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Massimo Giovannini

The characterization and modeling of polarized foregrounds has become a critical issue in the quest for primordial $B$-modes. A typical method to proceed is to factorize and parametrize the spectral properties of foregrounds and their scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 S. Azzoni , M. H. Abitbol , D. Alonso , A. Gough , N. Katayama , T. Matsumura

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is based on the maximum a-posteriori…

Astrophysics · Physics 2008-12-21 Liron Gleser , Adi Nusser , Andrew J. Benson

The curl (B) modes of cosmic microwave background (CMB) polarization anisotropies are a unique probe of the primordial background of inflationary gravitational waves (IGWs). Unfortunately, the B-mode polarization anisotropies generated by…

Astrophysics · Physics 2007-05-23 Kris Sigurdson , Asantha Cooray

In inflationary models, gravitational waves are produced and generate B-type polarization in the CMB. Since B polarization is only generated by gravity waves it does not suffer from the cosmic variance. A perfect decomposition of the CMB…

Astrophysics · Physics 2009-11-13 Mihail Amarie , Christopher Hirata , Uros Seljak

We investigate the potential of second generation measurements of redshifted 21 cm radiation from before and during the epoch of reionization (EOR) to reconstruct the matter density fluctuations along the line of sight. To do so we…

Astrophysics · Physics 2008-11-26 Oliver Zahn , Matias Zaldarriaga
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