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A convincing detection of primordial non-Gaussianity in the cosmic background radiation (CMB) is essential to probe the physics of the early universe. Since a single statistical estimator can hardly be suitable to detect the various…

宇宙学与河外天体物理 · 物理学 2013-10-11 W. Cardona , A Bernui , M. J. Reboucas

We present an analytic approach to the estimation of beam asymmetry effects in CMB temperature and linear polarization anisotropy experiments. We derive via perturbative expansions simple and accurate results for the case of an elliptical…

天体物理学 · 物理学 2009-11-06 P. Fosalba , O. Doré , F. R. Bouchet

We constrain spatially-flat tilted and nonflat untilted scalar field ($\phi$) dynamical dark energy inflation ($\phi$CDM) models by using Planck 2015 cosmic microwave background (CMB) anisotropy measurements and recent baryonic acoustic…

宇宙学与河外天体物理 · 物理学 2019-04-29 Chan-Gyung Park , Bharat Ratra

We investigate the anisotropy in cosmic microwave background Planck maps due to the coupling between its beam asymmetry and uneven scanning strategy. Introducing a pixel space estimator based on the temperature gradients, we find a highly…

宇宙学与河外天体物理 · 物理学 2014-07-17 Ben Rathaus , Ely D. Kovetz

We use the Cosmic Microwave Background (CMB) anisotropy data from Planck to constrain the spatial fluctuations of the fine-structure constant \alpha. Through Thompson scattering of CMB photons, spatial anisotropies of \alpha lead to…

宇宙学与河外天体物理 · 物理学 2013-06-07 Jon O'Bryan , Joseph Smidt , Francesco De Bernardis , Asantha Cooray

Upcoming surveys will measure the cosmic microwave background (CMB) weak lensing power spectrum in exquisite detail, allowing for strong constraints on the sum of neutrino masses among other cosmological parameters. Standard CMB lensing…

宇宙学与河外天体物理 · 物理学 2024-08-23 Delon Shen , Emmanuel Schaan , Simone Ferraro

As the Cosmic Microwave Background (CMB) radiation is observed to higher and higher angular resolution the size of the resulting datasets becomes a serious constraint on their analysis. In particular current algorithms to determine the…

天体物理学 · 物理学 2007-05-23 Julian Borrill

Observations of the Cosmic Microwave Background (CMB) have cemented the notion that the large-scale Universe is both statistically homogeneous and isotropic. But is it invariant also under reflections? To probe this we require…

宇宙学与河外天体物理 · 物理学 2023-09-25 Oliver H. E. Philcox

The majority of present efforts to constrain cosmological parameters with cosmic microwave background (CMB) anisotropy data employ approximate likelihood functions, the time consuming nature of a complete analysis being a major obstacle. We…

天体物理学 · 物理学 2007-05-23 M. Douspis , J. G. Bartlett , A. Blanchard , M. Le Dour

We develop the transport operator formalism, a new line-of-sight integration framework to calculate the anisotropies of the Cosmic Microwave Background (CMB) at the linear and non-linear level. This formalism utilises a transformation…

宇宙学与河外天体物理 · 物理学 2015-09-25 Christian Fidler , Kazuya Koyama , Guido W. Pettinari

A flexible maximum-entropy component separation algorithm is presented that accommodates anisotropic noise, incomplete sky-coverage and uncertainties in the spectral parameters of foregrounds. The capabilities of the method are determined…

天体物理学 · 物理学 2009-11-07 R. B. Barreiro , M. P. Hobson , A. J. Banday , A. N. Lasenby , V. Stolyarov , P. Vielva , K. M. Gorski

We constrain several models of the early Universe that predict a statistical anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9 maps deconvolved with beam asymmetries. As compared to previous releases of WMAP…

宇宙学与河外天体物理 · 物理学 2014-03-03 Sabir Ramazanov , Grigory Rubtsov

This article constructs flat-sky approximations in a controlled way in the context of the cosmic microwave background observations for the computation of both spectra and bispectra. For angular spectra, it is explicitly shown that there…

宇宙学与河外天体物理 · 物理学 2015-05-20 Francis Bernardeau , Cyril Pitrou , Jean-Philippe Uzan

To probe cosmological fields beyond the Gaussian level, three-point statistics can be used, all of which are related to the bispectrum. Hence, measurements of CMB anisotropies, galaxy clustering, and weak gravitational lensing alike have to…

宇宙学与河外天体物理 · 物理学 2010-02-03 B. Joachimi , X. Shi , P. Schneider

We use a separable mode expansion estimator with WMAP data to estimate the bispectrum for all the primary families of non-Gaussian models. We review the late-time mode expansion estimator methodology which can be applied to any…

宇宙学与河外天体物理 · 物理学 2015-05-19 J. R. Fergusson , M. Liguori , E. P. S. Shellard

Starting from the exact non-linear description of matter and radiation, a fully covariant and gauge-invariant formula for the observed temperature anisotropy of the cosmic microwave background (CBR) radiation, expressed in terms of the…

广义相对论与量子宇宙学 · 物理学 2009-10-30 Peter K. S. Dunsby

We consider the 2D wavelet transform with two scales to study sky maps of temperature anisotropies in the cosmic microwave background radiation (CMB). We apply this technique to simulated maps of small sky patches of size 12.8 \times 12.8…

To minimize instrumentally induced systematic errors, cosmic microwave background (CMB) anisotropy experiments measure temperature differences across the sky using paires of horn antennas, temperature map is recovered from temperature…

天体物理学 · 物理学 2009-08-30 Hao Liu , Ti-Pei Li

This article describes the computation of cosmic microwave background anisotropies in a universe with multi-connected spatial sections and focuses on the implementation of the topology in standard CMB computer codes. The key ingredient is…

天体物理学 · 物理学 2009-11-07 Alain Riazuelo , Jean-Philippe Uzan , Roland Lehoucq , Jeffrey Weeks

We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat $\Lambda$CDM model. Unlike…

宇宙学与河外天体物理 · 物理学 2018-09-19 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama
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