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Reliable extraction of cosmological information from observed cosmic microwave background (CMB) maps may require removal of strongly foreground contaminated regions from the analysis. In this article, we employ an artificial neural network…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-13 Srikanta Pal , Pallav Chanda , Rajib Saha

We describe a sampling method to estimate the polarized CMB signal from observed maps of the sky. We use a Metropolis-within-Gibbs algorithm to estimate the polarized CMB map, containing Q and U Stokes parameters at each pixel, and its…

Upcoming cosmic microwave background (CMB) experiments are expected to detect new signals probing interaction of CMB photons with intervening large-scale structure. Among these the moving-lens effect, the CMB temperature anisotropy induced…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-24 Selim C. Hotinli , Elena Pierpaoli

The natural outcome of theoretical calculations of microwave background anisotropy is the angular power spectrum ${\cal C}_\ell$ as a function of multipole number $\ell$. Experimental ${\cal C}_\ell$'s are needed for direct comparison.…

Astrophysics · Physics 2009-09-25 J. Richard Bond

Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 Md Ishaque Khan , Rajib Saha

Forthcoming CMB experiments will allow us to accurately investigate the power spectrum at very small scales ($\ell > 1000$). We predict the level of the primary anisotropies, given the actual CMB measurements. The secondary anisotropies…

Astrophysics · Physics 2009-11-07 N. Aghanim , P. G. Castro , A. Melchiorri , J. Silk

In this paper we derive a full expression for the propagation of weak lensing shape measurement biases into cosmic shear power spectra including the effect of missing data. We show using simulations that terms higher than first order in…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-16 T. D. Kitching , A. C. Deshpande , P. L. Taylor

The measurement of the large-scale B-mode polarization in the cosmic microwave background (CMB) is a fundamental goal of future CMB experiments. However, because of unprecedented sensitivity, future CMB experiments will be much more…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-16 M. Remazeilles , C. Dickinson , H. K. K. Eriksen , I. K. Wehus

Weak lensing of the CMB changes the unlensed temperature anisotropy and polarization power spectra. Accounting for the lensing effect will be crucial to obtain accurate parameter constraints from sensitive CMB observations. Methods for…

Astrophysics · Physics 2009-11-10 Anthony Challinor , Antony Lewis

CMB photons travel from the last scattering surface, when the primary CMB has been generated, along the surface of the light cone to us. During their travel, they are affected by many secondary effects such as the integrated Sachs-Wolfe…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-11 Mario Ballardini

Recent measurements of the temperature field of Cosmic Microwave Background (CMB) provide tantalising evidence for violation of Statistical Isotropy (SI) that constitutes a fundamental tenet of contemporary cosmology. CMB space based…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Suvodip Mukherjee , Tarun Souradeep

In experimental microwave maps, point-sources can strongly affect the estimation of the power-spectrum and/or the test of Gaussianity of the Cosmic Microwave Background (CMB) component. As a consequence, their removal from the sky maps…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Elsa Patricia R. G. Ramos , Roberto Vio , Paola Andreani

[Abridged] We have produced a cleaned map of the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data using an improved foreground subtraction technique. We perform an internal linear combination (ILC) to subtract the Galactic foreground…

Astrophysics · Physics 2008-11-26 Chan-Gyung Park , Changbom Park , J. Richard Gott

The rapidly improving precision of measurements of gravitational lensing of the Cosmic Microwave Background (CMB) also requires a corresponding increase in the precision of theoretical modeling. A commonly made approximation is to model the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Vanessa Böhm , Marcel Schmittfull , Blake D. Sherwin

The nearly scale-invariant primordial power spectrum provides the standard initial conditions for cosmological perturbations. However, the largest scales remain only weakly constrained by CMB observations, leaving room for deviations such…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-19 Ujjwal Upadhyay , Yashi Tiwari , Tarun Souradeep

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

This work describes Cosmic Microwave Background (CMB) data analysis algorithms and their implementations, developed to produce a pixelized map of the sky and a corresponding pixel-pixel noise correlation matrix from time ordered data for a…

Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

This is the second paper in the series that confronts predictions of a model of the landscape with cosmological observations. We show here how the modifications of the Friedmann equation due to the decohering effects of long wavelength…

High Energy Physics - Theory · Physics 2008-11-26 R. Holman , Laura Mersini-Houghton , Tomo Takahashi

We investigate two possible explanations for the large-angle anomalies in the Cosmic Microwave Background (CMB): an intrinsically anisotropic model and an inhomogeneous model. We take as an example of the former a Bianchi model (which…

Astrophysics · Physics 2009-11-13 Kate Land , Joao Magueijo