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相关论文: Dipole Modulation in Tensor Modes: Signatures in C…

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Inspired by a dipole asymmetric template for the CMB temperature map in the primordial scalar fluctuations observed by Planck at a large scale, we examine the contribution of a similar template for power asymmetry in modifying the linear…

广义相对论与量子宇宙学 · 物理学 2023-08-01 Jafar Khodagholizadeh , Rohoollah Mohammadi , S. M. S. Movahed

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

The connection between the dipolar modulation asymmetry and the quadrupole-octopole alignment in the CMB is studied in this work. First, a generalization of the dipolar modulation model is proposed by considering that the amplitude may…

宇宙学与河外天体物理 · 物理学 2019-11-06 A. Marcos-Caballero , E. Martínez-González

By decomposing the CMB temperature fluctuations \emph{squared} into spherical harmonics, we can define the \emph{CMB power multipoles} as the fundamental observables to quantify any generic modulations in the CMB. This allows for simple…

宇宙学与河外天体物理 · 物理学 2014-01-09 Lingfei Wang

The hemispherical power asymmetry, observed in the CMBR data, has generally been interpreted in terms of the dipole modulation model for the temperature fluctuations. Here we point out that this model leads to several predictions, which can…

宇宙学与河外天体物理 · 物理学 2017-10-31 Pranati K. Rath , Pankaj Jain

Measurements of the cosmic microwave background (CMB) temperature anisotropies have revealed a dipolar asymmetry in power at the largest scales, in apparent contradiction with the statistical isotropy of standard cosmological models. The…

宇宙学与河外天体物理 · 物理学 2018-03-07 D. Contreras , J. Hutchinson , A. Moss , D. Scott , J. P. Zibin

Anomalies in the large-scale CMB temperature sky measured by WMAP have been suggested as possible evidence for a violation of statistical isotropy on large scales. In any physical model for broken isotropy, there are testable consequences…

天体物理学 · 物理学 2008-12-18 Cora Dvorkin , Hiranya V. Peiris , Wayne Hu

We consider the effects of entanglement in the initial quantum state of scalar and tensor fluctuations during inflation. We allow the gauge-invariant scalar and tensor fluctuations to be entangled in the initial state and compute…

高能物理 - 理论 · 物理学 2017-01-13 Nadia Bolis , Andreas Albrecht , R. Holman

Lensing of the CMB by modes that are larger than the size of the survey dilates intrinsic scales in the temperature and polarization fields and coherently shifts their observed power spectra with respect to the ensemble or all-sky mean. The…

宇宙学与河外天体物理 · 物理学 2014-07-09 Alessandro Manzotti , Wayne Hu , Aurélien Benoit-Lévy

One of the most intriguing hints of a departure from the standard cosmological model is a large-scale dipolar power asymmetry in the cosmic microwave background (CMB). If not a statistical fluke, its origins must lie in the modulation of…

宇宙学与河外天体物理 · 物理学 2017-03-23 J. P. Zibin , D. Contreras

We conduct a model-independent analysis of temporal features during inflation in the large-scale CMB temperature power spectrum allowing for the possibility of non-negligible tensor contributions. Of 20 principal components of the…

宇宙学与河外天体物理 · 物理学 2018-09-18 V Miranda , Wayne Hu , Cora Dvorkin

The largest temperature anisotropy in the cosmic microwave background (CMB) is the dipole. The simplest interpretation of the dipole is that it is due to our motion with respect to the rest frame of the CMB. As well as creating the $\ell$=1…

宇宙学与河外天体物理 · 物理学 2021-11-25 Raelyn M. Sullivan , Douglas Scott

I propose a model of dipole modulation in Cosmic Background Microwave Radiation (CMBR) polarization fields Q and U. It is shown that the modulation leads to correlations between l and l multipoles where either l = l or l = l \pm 1, but the…

宇宙学与河外天体物理 · 物理学 2015-10-06 Rahul Kothari

Both the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck observations reported the hemispherical asymmetry of the cosmic microwave background (CMB) temperature fluctuation. The hemispherical asymmetry might be stemmed from the…

宇宙学与河外天体物理 · 物理学 2014-05-13 Zhe Chang , Sai Wang

The observed hemispherical asymmetry in CMB map can be explained by modulation from a long wavelength super horizon mode which non-linearly couples to the CMB modes. We address the criticism in [1] about the role of non-Gaussianities in…

宇宙学与河外天体物理 · 物理学 2015-06-19 Mohammad Hossein Namjoo , Ali Akbar Abolhasani , Shant Baghram , Hassan Firouzjahi

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 investigate a possibility of constraining statistical anisotropies of the primordial tensor perturbations by using future observations for the Cosmic Microwave Background (CMB) B-mode polarization. By parameterizing a…

宇宙学与河外天体物理 · 物理学 2018-10-24 Takashi Hiramatsu , Shuichiro Yokoyama , Tomohiro Fujita , Ippei Obata

An observer in relative motion to the Cosmic Microwave Background (CMB) rest frame is sensitive to both aberration and Doppler effects. Both effects introduce similar but non-identical off-diagonal couplings in the spherical harmonic…

宇宙学与河外天体物理 · 物理学 2021-09-06 Pedro da Silveira Ferreira , Miguel Quartin

Spectral distortions of the cosmic microwave background (CMB) may become a powerful probe of primordial perturbations at small scales. Existing studies of spectral distortions focus almost exclusively on primordial scalar metric…

宇宙学与河外天体物理 · 物理学 2015-06-22 Jens Chluba , Liang Dai , Daniel Grin , Mustafa A. Amin , Marc Kamionkowski

Recently, BICEP2 measurements of the cosmic microwave background (CMB) $B$-mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of $r=0.2$ when assuming nearly…

高能物理 - 唯象学 · 物理学 2015-06-22 Guo-Chin Liu , Kin-Wang Ng , I-Chin Wang
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