Formulation and constraints on decaying dark matter with finite mass daughter particles
Formulation and constraints on decaying dark matter with finite mass daughter particles
复制标题
具有有限质量子粒子的衰变暗物质的公式和约束
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
N. Sugiyama
中科院分区：
文献类型：
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作者：
S. Aoyama;K. Ichiki;Daisuke Nitta;N. Sugiyama
衰变暗物质宇宙学模型已经被提出，以弥补标准冷暗物质范式中小尺度的生产过剩问题。我们考虑一个衰变暗物质模型，其中一个CDM母粒子衰变成两个具有任意质量的子粒子。导出了一套完整的暗物质粒子玻尔兹曼方程，用来计算暗物质粒子的能量密度演化和密度微扰。通过比较该模型中宇宙的膨胀历史和子粒子的自由流动尺度与天文观测数据，给出了母粒子寿命的约束条件，以及子粒子与母粒子的质量比mRmD/mRmM。从宇宙微波背景到最后一个散射面的距离，在子粒子的无质量极限下，我们得到了$Gamma^-1>；$30Gyr；另一方面，在极限为0$的情况下，我们得到了$m_(-1)&$gt；$0.97$m_(-1)。自由流动约束将质量比的界限收紧为$(\Gamma^{-1}/10^{-2}{\rm Gyr})\less sim((1-m_{\rm d1}/m_{\rm M})/10^{-2})^{-3/2}$\Gamma^{-1}<；H^{-1}(z=3)$。
Decaying dark matter cosmological models have been proposed to remedy the overproduction problem at small scales in the standard cold dark matter paradigm. We consider a decaying dark matter model in which one CDM mother particle decays into two daughter particles, with arbitrary masses. A complete set of Boltzmann equations of dark matter particles is derived which is necessary to calculate the evolutions of their energy densities and their density perturbations. By comparing the expansion history of the universe in this model and the free-streaming scale of daughter particles with astronomical observational data, we give constraints on the lifetime of the mother particle, $\Gamma^{-1}$, and the mass ratio between the daughter and the mother particles $m_{\rm D}/m_{\rm M}$. From the distance to the last scattering surface of the cosmic microwave background, we obtain $\Gamma^{-1}>$ 30 Gyr in the massless limit of daughter particles and, on the other hand, we obtain $m_{\rm D} >$ 0.97$m_{\rm M}$ in the limit $\Gamma^{-1}\to 0$. The free-streaming constraint tightens the bound on the mass ratio as $(\Gamma^{-1}/10^{-2}{\rm Gyr}) \lesssim ((1-m_{\rm D1}/m_{\rm M})/10^{-2})^{-3/2}$ for $\Gamma^{-1} < H^{-1}(z=3)$.
影响因子：
8.7
作者：
Komatsu, E.;Smith, K. M.;Wright, E. L.
通讯作者：
Wright, E. L.