Impact of a primordial magnetic field on cosmic microwave background B modes with weak lensing
Impact of a primordial magnetic field on cosmic microwave background B modes with weak lensing
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弱透镜作用下原始磁场对宇宙微波背景 B 模式的影响
DOI：
10.1103/physrevd.97.103525
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发表时间：
2018
影响因子：
5
通讯作者：
Dai. G. Yamazaki
中科院分区：
文献类型：
--
作者：
Dai G. Yamazaki;Dai. G. Yamazaki
我们讨论了原始磁场（PMF）由于弱透镜（WL）效应而抑制宇宙微波背景（CMB）模式的方式。 WL 效应取决于物质扰动引起的透镜势 (LP)，其在宇宙尺度上的分布由物质功率谱 (MPS) 给出。因此，WL对CMB模式的影响受到MPS的影响。考虑到 PMF 的系综平均能量密度（我们称之为“背景 PMF”）对 MPS 的影响，MPS 的振幅在 的波数范围内受到抑制。 MPS影响CMB模式下的LP和WL效果；然而，PMF 可以抑制这种影响。先前对带有 PMF 的 CMB 模式的研究仅考虑了矢量和张量模式。这些模式增强了多极范围内的 CMB 模式，而背景 PMF 由于整个多极范围内的 WL 效应而抑制了 CMB 模式。宇宙中的物质密度控制着 WL 效应。因此，当我们从宇宙学观测数据集（包括 CMB 模式）约束 PMF 和物质密度参数时，我们预计这些参数之间存在简并性。 CMB模式还通过宇宙学参数搜索提供有关背景引力波、暴胀理论、物质密度涨落以及宇宙学尺度的结构形成的重要信息。如果我们研究这些主题并正确约束来自宇宙学观测的宇宙学参数（包括 CMB 模式），我们需要正确考虑背景 PMF。
We discuss the manner in which the primordial magnetic field (PMF) suppresses the cosmic microwave background (CMB)mode due to the weak-lensing (WL) effect. The WL effect depends on the lensing potential (LP) caused by matter perturbations, the distribution of which at cosmological scales is given by the matter power spectrum (MPS). Therefore, the WL effect on the CMBmode is affected by the MPS. Considering the effect of the ensemble average energy density of the PMF, which we call “the background PMF,” on the MPS, the amplitude of MPS is suppressed in the wave number range of. The MPS affects the LP and the WL effect in the CMBmode; however, the PMF can damp this effect. Previous studies of the CMBmode with the PMF have only considered the vector and tensor modes. These modes boost the CMBmode in the multipole range of, whereas the background PMF damps the CMBmode owing to the WL effect in the entire multipole range. The matter density in the Universe controls the WL effect. Therefore, when we constrain the PMF and the matter density parameters from cosmological observational data sets, including the CMBmode, we expect degeneracy between these parameters. The CMBmode also provides important information on the background gravitational waves, inflation theory, matter density fluctuations, and the structure formations at the cosmological scale through the cosmological parameter search. If we study these topics and correctly constrain the cosmological parameters from cosmological observations, including the CMBmode, we need to correctly consider the background PMF.