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相关论文: Testing the Dipole Modulation Model in CMBR

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A common explanation for the CMB power asymmetry is to introduce a dipolar modulation at the stage of inflation, where the primordial power spectrum is spatially varying. If the universe in the stage of inflation is Finslerian, and if the…

宇宙学与河外天体物理 · 物理学 2017-06-28 Xin Li , Hai-Nan Lin

We explore the hemispherical asymmetry predicted in cosmic microwave background polarization when there is an asymmetry in temperature anisotropies due to primordial perturbations. We consider the cases of asymmetries due to adiabatic and…

宇宙学与河外天体物理 · 物理学 2015-05-20 M. H. Namjoo , A. A. Abolhasani , H. Assadullahi , S. Baghram , H. Firouzjahi , D. Wands

In the frame of the Solar System, the Doppler and aberration effects cause distortions in the form of mode couplings in the cosmic microwave background (CMB) temperature and polarization power spectra and hence impose biases on the…

宇宙学与河外天体物理 · 物理学 2020-03-04 Siavash Yasini , Elena Pierpaoli

We perform a comparison of WMAP 9-year (WMAP9) and Planck 2015 cosmic microwave background (CMB) temperature power spectra across multipoles $30\leq\ell\leq1200$. We generate simulations to estimate the correlation between the two datasets…

宇宙学与河外天体物理 · 物理学 2019-01-01 Yajing Huang , Graeme E. Addison , Janet L. Weiland , Charles L. Bennett

Cosmic Microwave Background (CMB) experiments, such as WMAP and Planck, measure intensity anisotropies and build maps using a linearized formula for relating them to the temperature blackbody fluctuations. However, this procedure also…

宇宙学与河外天体物理 · 物理学 2016-08-17 Alessio Notari , Miguel Quartin

The Cosmic Radio Dipole is of fundamental interest to cosmology. Recent studies revealed open questions about the nature of the observed Cosmic Radio Dipole. We use simulated source count maps to test a linear and a quadratic estimator for…

宇宙学与河外天体物理 · 物理学 2021-12-07 Thilo M. Siewert , Matthias Schmidt-Rubart , Dominik J. Schwarz

In the present work, we study the largest structures of the CMB temperature measured by Planck in terms of the most prominent peaks on the sky, which, in particular, are located in the southern galactic hemisphere. Besides these large-scale…

宇宙学与河外天体物理 · 物理学 2017-05-17 A. Marcos-Caballero , E. Martínez-González , P. Vielva

The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, {\it i.e.} aberration, and a shift in their frequency, {\it i.e.} Doppler effect. Both effects distort the…

宇宙学与河外天体物理 · 物理学 2015-06-11 Riccardo Catena , Alessio Notari

The temperature fluctuations of the Cosmic Microwave Background (CMB) are supposed to be distributed randomly in both magnitude and phase, following to the simplest model of inflation. In this paper, we look at the odd and even multipoles…

宇宙学与河外天体物理 · 物理学 2015-03-19 M. Hansen , A. M. Frejsel , J. Kim , P. Naselsky , F. Nesti

We estimate CMB polarization and temperature power spectra using WMAP 5-year foreground contaminated maps. The power spectrum is estimated by using a model independent method, which does not utilize directly the diffuse foreground templates…

宇宙学与河外天体物理 · 物理学 2011-02-11 Pramoda Kumar Samal , Rajib Saha , Jacques Delabrouille , Simon Prunet , Pankaj Jain , Tarun Souradeep

The lack of power of large--angle CMB anisotropies is known to increase its statistical significance at higher Galactic latitudes, where a string--inspired pre--inflationary scale $\Delta$ can also be detected. Considering the Planck 2015…

宇宙学与河外天体物理 · 物理学 2018-03-13 A. Gruppuso , N. Kitazawa , M. Lattanzi , N. Mandolesi , P. Natoli , A. Sagnotti

We report a measurement of the E-mode polarization power spectrum of the cosmic microwave background (CMB) using 150 GHz data taken from July 2014 to December 2016 with the POLARBEAR experiment. We reach an effective polarization map noise…

We investigate the hemispherical power asymmetry in the cosmic microwave background on small angular scales. We find an anomalously high asymmetry in the multipole range l=601-2048, with a naive statistical significance of 6.5 sigma.…

宇宙学与河外天体物理 · 物理学 2013-09-30 Samuel Flender , Shaun Hotchkiss

We present posterior sample-based cosmic microwave background (CMB) constraints from Planck LFI and WMAP observations derived through global end-to-end Bayesian processing. We use these samples to study correlations between CMB, foreground,…

WMAP observations have accurately determined the position of the first two peaks and dips in the CMB temperature power spectrum. These encode information on the ratio of the distance to the last scattering surface to the sound horizon at…

天体物理学 · 物理学 2008-11-26 Pier Stefano Corasaniti , Alessandro Melchiorri

We investigate large-angle scale temperature anisotropy in the Cosmic Microwave Background (CMB) with the Wilkinson Microwave Anisotropy Probe (WMAP) data and model the large-angle anomalies as the effect of the CMB quadrupole anisotropies…

宇宙学与河外天体物理 · 物理学 2014-11-20 Li-Ping He , Quan Guo

Cosmic microwave background (CMB) temperature anisotropies encode the history of the universe, which manifest itself in the angular power spectrum. We test the angular power spectra of small patches from the ESA $\textit{Planck}$ data.…

宇宙学与河外天体物理 · 物理学 2021-02-04 Ming-Feng Ho , Lung-Yih Chiang

Large-scale modes in the temperature anisotropy power spectrum C_l measured by the Wilkinson Microwave Anisotropy Probe (WMAP), seem to have lower amplitudes (C_2, C_3 and C_4) than that expected in the so called concordance LCDM model. In…

天体物理学 · 物理学 2009-11-07 E. Gaztanaga , J. Wagg , T. Multamaki , A. Montana , D. H. Hughes

Asymmetric beams can create significant bias in estimates of the power spectra from CMB experiments. With the temperature power spectrum many orders of magnitude stronger than the B-mode power spectrum any systematic error that couples the…

宇宙学与河外天体物理 · 物理学 2017-03-08 Christopher G. R. Wallis , Michael L. Brown , Richard A. Battye , Giampaolo Pisano , Luca Lamagna