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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…

天体物理学 · 物理学 2009-11-10 Anthony Challinor , Antony Lewis

The recent Cosmic Microwave Background (CMB) measurements indicate that there is power deficiency of the CMB anisotropies at large scales compared with the $\Lambda$CDM model. We have investigated the possibility of explaining such effects…

天体物理学 · 物理学 2009-11-13 Rita Sinha , Tarun Souradeep

The purpose of the Cosmic Background Radiation (CBR) experiments is to measure the temperature anisotropy via the autocorrelation function. The partial wave $l_1$ corresponding to the first Doppler peak caused by baryon-photon oscillations…

天体物理学 · 物理学 2009-10-30 Paul H. Frampton , Y. Jack Ng , Ryan Rohm

We study statistical anisotropies generated in the observed two-point function of the cosmic microwave background (CMB) fluctuations if the primordial statistics are non-Gaussian. Focusing on the dipole modulations of the anisotropies, we…

宇宙学与河外天体物理 · 物理学 2018-07-17 Saroj Adhikari , Anne-Sylvie Deutsch , Sarah Shandera

Aberration kernels describe how harmonic-space multipole coefficients of cosmic microwave background (CMB) observables transform under Lorentz boosts of the reference frame. For spin-weighted CMB observables, transforming like the CMB…

宇宙学与河外天体物理 · 物理学 2014-06-09 Liang Dai , Jens Chluba

The weak lensing effects are known to change only weakly the shape of the power spectrum of the Cosmic Microwave Background (CMB) temperature fluctuations. I show here that they nonetheless induce specific non-Gaussian effects that can be…

天体物理学 · 物理学 2016-08-30 F. Bernardeau

On large angular scales (greater than about 60 degrees), the two-point angular correlation function of the temperature of the cosmic microwave background (CMB), as measured (outside of the plane of the Galaxy) by the Wilkinson Microwave…

宇宙学与河外天体物理 · 物理学 2015-05-18 Devdeep Sarkar , Dragan Huterer , Craig J. Copi , Glenn D. Starkman , Dominik J. Schwarz

We study the apparent lack of power on large angular scales in the WMAP data. We confirm that although there is no apparent lack of power at large angular scales for the full-sky maps, the lowest multipoles of the WMAP data happen to have…

天体物理学 · 物理学 2007-05-23 Amir Hajian

Cosmic microwave background (CMB) experiments generally infer a temperature fluctuation from a measured intensity fluctuation through the first term in the Taylor expansion of the Planck function, the relation between the intensity in a…

天体物理学 · 物理学 2009-11-07 M. Kamionkowski , Lloyd Knox

(Abridged)Motivated by the recent results of Hansen et al. (2008) concerning a noticeable hemispherical power asymmetry in the WMAP data on small angular scales, we revisit the dipole modulated signal model introduced by Gordon et al.…

宇宙学与河外天体物理 · 物理学 2011-02-11 J. Hoftuft , H. K. Eriksen , A. J. Banday , K. M. Gorski , F. K. Hansen , P. B. Lilje

We report results on an ``one-way light path'' laser diffraction experiment as a function of the laser beam alignment relative to the Earth's velocity vector obtained by COBE measurements of the Doppler shift in the cosmic microwave…

天体物理学 · 物理学 2007-05-23 C. E. Navia , C. R. A. Augusto

The scalar mode temperature fluctuations of the cosmic microwave background has been derived in a spatially closed universe from two different methods. First, by following the photon trajectory after the last scattering and then from the…

广义相对论与量子宇宙学 · 物理学 2017-09-27 Pedram Niazy , Amir H. Abbassi

We investigate a possible asymmetry in the statistical properties of the cosmic microwave background temperature field and to do so we construct an estimator aiming at detecting a dipolar modulation. Such a modulation is found to induce…

天体物理学 · 物理学 2009-11-10 Simon Prunet , Jean-Philippe Uzan , Francis Bernardeau , Tristan Brunier

Several satellite missions have uncovered a series of potential anomalies in the fluctuation spectrum of the cosmic microwave background temperature, including: (1) an unexpectedly low level of correlation at large angles, manifested via…

宇宙学与河外天体物理 · 物理学 2022-01-04 Fulvio Melia , Qingbo Ma , Jun-Jie Wei , Bo Yu

Second-order power spectra of Cosmic Microwave Background (CMB) anisotropies due to random primordial perturbations at the matter dominant stage are studied, based on the relativistic second-order theory of perturbations in flat…

天体物理学 · 物理学 2008-11-26 Kenji Tomita

We consider the weak lensing effect induced by linear cosmological perturbations on the cosmic microwave background (CMB) polarization anisotropies. We find that the amplitude of the lensing peak in the BB mode power spectrum is a faithful…

天体物理学 · 物理学 2009-11-13 Viviana Acquaviva , Carlo Baccigalupi

See comments. We calculate analytically an effect of the thermal Comptonization on the cosmic microwave background (CMB) photons when they propagate through galaxy clusters. We estimate a deformation of the CMB spectrum due to multiple…

宇宙学与河外天体物理 · 物理学 2019-11-26 Lev Titarchuk , Galina Lipunova

Calculations of the Cosmic Microwave Background lensing power implemented into the standard cosmological codes such as CAMB and CLASS usually treat the surface of last scatter as an infinitely thin screen. However, since the CMB…

宇宙学与河外天体物理 · 物理学 2020-06-02 Boryana Hadzhiyska , David Spergel , Joanna Dunkley

We introduce a $\textit{frequency-dependent}$ Doppler and aberration transformation kernel for the harmonic multipoles of a general cosmological observable with spin weight $s$, Doppler weight $d$ and arbitrary frequency spectrum. In the…

宇宙学与河外天体物理 · 物理学 2017-11-08 Siavash Yasini , Elena Pierpaoli