Neutrino mass effects on vector and tensor CMB anisotropies in the presence of a primordial magnetic field
Neutrino mass effects on vector and tensor CMB anisotropies in the presence of a primordial magnetic field
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DOI：
10.1103/physrevd.78.045010
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发表时间：
2008-06
影响因子：
5
通讯作者：
K. Kojima;K. Ichiki;D. G. Yamazaki;T. Kajino;G. Mathews
中科院分区：
文献类型：
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作者：
K. Kojima;K. Ichiki;D. G. Yamazaki;T. Kajino;G. Mathews
如果在光子解耦期间和之后存在原始磁场（PMF），则有限的中微子质量可以影响CMB的所有模式。在这项工作中，我们通过在存在大质量中微子和PMF的情况下构建矢量和张量模式方程，扩展了先前对标量模式效应的研究。我们在一个示例中计算了各种模式的功率谱，发现当PMF存在时，中微子质量会显著影响矢量和张量模式，而在没有PMF的情况下，这种影响可以忽略不计。本分析最突出的结果是低多极张量模的类梯度功率谱（EE）分量的行为。对于大质量中微子，EE模式可以与观测到的主要各向异性相媲美。因此，如果和当在低多极下测量EE模式功率谱时，存在对中微子质量总和施加强约束的可能性。
If a primordial magnetic field (PMF) is present during photon decoupling and afterward, a finite neutrino mass can affect all modes of the CMB. In this work, we expand on earlier studies of the scalar mode effects by constructing the vector and tensor-mode equations in the presence of massive neutrinos and a PMF. We compute the power spectrum of the various modes in an illustrative example and find that the neutrino mass can significantly affect the vector and tensor modes when a PMF exists, while the effects are negligible for no PMF. The most prominent result of the present analysis is the behavior of the EE (grad-like polarization power spectrum) component of the tensor mode at low multipoles. For massive neutrinos the EE mode can become comparable to the observed primary anisotropy. Therefore, if and when the EE mode power spectrum is measured at low multipoles the possibility exists to place a strong constraint on the sum of the neutrino masses.