تقرير
Asymmetry of the CMB map: local and global anomalies
| العنوان: | Asymmetry of the CMB map: local and global anomalies |
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| المؤلفون: | Creswell, James, Naselsky, Pavel |
| سنة النشر: | 2021 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Cosmology and Nongalactic Astrophysics |
| الوصف: | We investigate the sources of parity asymmetry in the CMB temperature maps using a pixel domain approach. We demonstrate that this anomaly is mainly associated with the presence of two pairs of high asymmetry regions. The first pair of peaks with Galactic coordinates $(l, b) = (212^\circ, -21^\circ)$ and $(32^\circ, 21^\circ)$ is associated with the Northern Galactic Spur and the direction of the dipole modulation of the power spectrum of the CMB anisotropy. The other pair ($(l, b)=(332^\circ, -8^\circ)$ and $(152^\circ, 8^\circ)$) is located within the Galactic plane (the Galactic Cold Spot and its antipodal partner). Similar asymmetric peaks, but with smaller amplitudes, belong to the WMAP/Planck Cold Spot and its partner in the Northern Galactic Spur. These local anomalies increase the odd-multipole power to a level consistent with Gaussian simulations. In contrast, the deficit of symmetric peaks is accompanied by a deficit in the even-multipole power and is the source of the parity asymmetry of the CMB temperature maps at the level of about 3 sigma. We also evaluate the influence of the quadrupole, which is another source of the even-multipole deficit. If the low quadrupole is an intrinsic feature of the theoretical model, it will reduce the significance of the parity asymmetry to around the 2 sigma level. We also investigate the relationship between the asymmetry of the power spectrum and the level of the parity asymmetry in the framework of a model with dipole modulation of a statistically uniform Gaussian signal. We show that these two anomalies are innately linked to each other. Comment: 15 pages, 10 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1088/1475-7516/2021/03/103 |
| URL الوصول: | http://arxiv.org/abs/2102.13442 |
| رقم الأكسشن: | edsarx.2102.13442 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1088/1475-7516/2021/03/103 |
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