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The large-angle, low multipole cosmic microwave background (CMB) provides a unique view of the largest angular scales in the Universe. Study of these scales is hampered by the facts that we have only one Universe to observe, only a few…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Craig J. Copi , Dragan Huterer , Dominik J. Schwarz , Glenn D. Starkman

Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-C_l…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 H. F. Gruetjen , E. P. S. Shellard

Measurement of the angular power spectrum of the cosmic microwave background is most often based on a spherical harmonic analysis of the observed temperature anisotropies. Even if all-sky maps are obtained, however, it is likely that the…

Astrophysics · Physics 2009-10-31 Daniel J. Mortlock , Anthony D. Challinor , Michael P. Hobson

We attempt to make a direct measurement of the weak lensing signal from the WMAP 7-year data. We apply the real-space implementation of the optimal quadratic estimator on the maps produced by the W-band Differencing Assemblies. We obtain a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 C. Sofia Carvalho , Ismael Tereno , Spyros Basilakos

Upcoming photometric lensing surveys will considerably tighten constraints on the neutrino mass and the dark energy equation of state. Nevertheless it remains an open question of how to optimally extract the information and how well the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 Peter L. Taylor , Thomas D. Kitching , Jason D. McEwen

Based on realistic simulations, we propose an hybrid method to reconstruct the lensing potential power spectrum, directly on PLANCK-like CMB frequency maps. It implies using a large galactic mask and dealing with a strong inhomogeneous…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 S. Plaszczynski , A. Lavabre , L. Perotto , J. -L. Starck

The CMB maps obtained by observations always possess domains which have to be masked due to severe uncertainties with respect to the genuine CMB signal. Cosmological analyses ideally use full CMB maps in order to get e.g. the angular power…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 R. Aurich , S. Lustig

Reconstruction of gravitational lensing effects in the CMB from current and upcoming surveys is still dominated by temperature anisotropies. Extragalactic foregrounds in temperature maps can induce significant biases in the lensing power…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-25 Frank J. Qu , Anthony Challinor , Blake D. Sherwin

Precise reconstruction of the cosmic microwave background lensing potential can be achieved with deep polarization surveys by iteratively removing lensing-induced $B$ modes. We introduce a lensing spectrum estimator and its likelihood for…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-13 Louis Legrand , Julien Carron

A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables the extraction of useful information from…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 Fergus Simpson , J. Berian James , Alan F. Heavens , Catherine Heymans

Aiming to extract cosmological information from linear scales of the WISE$\times$SuperCOSMOS photometric redshift catalog, we perform a characterization of the systematic effects associated with stellar content, evidencing the presence of…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-11 H. S. Xavier , M. V. Costa-Duarte , A. Balaguera-Antolínez , M. Bilicki

Most analysis of Cosmic Microwave Background spherical harmonic coefficients a_lm has focused on estimating the power spectrum C_l=<|a_lm|^2> rather than the coefficients themselves. We present a minimum-variance method for measuring a_lm…

Astrophysics · Physics 2009-10-07 Angelica de Oliveira-Costa , Max Tegmark

The all-sky 408 MHz map of Haslam et al. is one the most important total-power radio surveys. It has been widely used to study diffuse synchrotron radiation from our Galaxy and as a template to remove foregrounds in cosmic microwave…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. Remazeilles , C. Dickinson , A. J. Banday , M. -A. Bigot-Sazy , T. Ghosh

Many recent analyses have indicated that large scale WMAP data display anomalies that appear inconsistent with the standard cosmological paradigm. However, the effects of foreground contamination, which require elimination of some fraction…

Astrophysics · Physics 2009-11-10 Anze Slosar , Uros Seljak

We present a semi-analytical method to investigate the systematic effects and statistical uncertainties of the calculated angular power spectrum when incomplete spherical maps are used. The computed power spectrum suffers in particular a…

Instrumentation and Methods for Astrophysics · Physics 2014-11-20 R. Ansari , C. Magneville

We search for planar deviations of statistical isotropy in the Wilkinson Microwave Anisotropy Probe (WMAP) data by applying a recently introduced angular-planar statistics both to full-sky and to masked temperature maps, including in our…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 L. Raul Abramo , Armando Bernui , Thiago S. Pereira

The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of…

Astrophysics · Physics 2009-11-10 A. Slosar , U. Seljak , A. Makarov

We revisit a recently introduced power spectrum estimation technique based on Gibbs sampling, with the goal of applying it to the high-resolution WMAP data. In order to facilitate this analysis, a number of sophistications have to be…

Estimation of the angular power spectrum of the Cosmic Microwave Background (CMB) on a small patch of sky is usually plagued by serious spectral leakage, specially when the map has a hard edge. Even on a full sky map, point source masks can…

Astrophysics · Physics 2009-11-06 Sudeep Das , Amir Hajian , David N. Spergel

The study of the Cosmic Microwave Background (CMB) lensing potential has established itself by now as a robust way of probing the physics of large-scale structure growth. The most common estimators of the lensing potential are derived under…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Dominic Beck , Giulio Fabbian , Josquin Errard
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