We investigate the constraints on total neutrino mass in the scenario of vacuum energy interacting with cold dark matter. We focus on two typical interaction forms, i.e., $Q=βHρ_{\rm c}$ and $Q=βHρ_Λ$. To avoid the occurrence of large-scale instability in interacting dark energy cosmology, we adopt the parameterized post-Friedmann approach to calculate the perturbation evolution of dark energy. We employ observational data, including the Planck cosmic microwave background temperature and polarization data, baryon acoustic oscillation data, a JLA sample of type Ia supernovae observation, direct measurement of the Hubble constant, and redshift space distortion data. We find that, compared with those in the $Λ$CDM model, much looser constraints on $\sum m_ν$ are obtained in the $Q=βHρ_{\rm c}$ model, whereas slightly tighter constraints are obtained in the $Q=βHρ_Λ$ model. Consideration of the possible mass hierarchies of neutrinos reveals that the smallest upper limit of $\sum m_ν$ appears in the degenerate hierarchy case. By comparing the values of $χ^2_{\rm min}$, we find that the normal hierarchy case is favored over the inverted one. In particular, we find that the difference $Δχ^2_{\rm min} \equiv χ^2_{\rm IH; min}-χ^2_{\rm NH; min}> 2$ in the $Q=βHρ_{\rm c}$ model. In addition, we find that $β=0$ is consistent with the current observations in the $Q=βHρ_{\rm c}$ model, and $β< 0$ is favored at more than the $1σ$ level in the $Q=βHρ_Λ$ model.
Constraints on the sum of neutrino masses using cosmological data including the latest extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample
Intracluster Light as a Probe for Dark Matter: Exploring Self-interacting Dark Matter and Cold Dark Matter with C-EAGLE Sims
Korea Astronomy and Space Science Institute (KASI)（韩国天文学与空间科学研究所）；Quantum Universe Center, Korea Institute for Advanced Study（量子宇宙中心，韩国高等研究院）；School of Physics, The University of Sydney（悉尼大学物理学院）；ARC Centre of Excellence for Dark Matter Particle Physics（暗物质粒子物理卓越研究中心）；Departamento de Física Teórica, Facultad de Ciencias M-8, Universidad Autónoma de Madrid（马德里自治大学理学院M-8理论物理系）；Natural Science Research Institute (NSRI), University of Seoul（首尔大学自然科学研究所）；School of Physics, Korea Institute for Advanced Study（韩国高等研究院物理学院）；School of Physics and Astronomy, University of Nottingham（诺丁汉大学物理与天文学院）；Center for Advanced Computation, Korea Institute for Advanced Study（韩国高等研究院先进计算中心）；University of Science and Technology (UST)（科学技术院）
Feebly Self-Interacting Cold Dark Matter: New theory for the Core-Halo structure in GLSB Galaxies
本文研究了弱自相互作用冷暗物质的低能宇宙动力学，并对大质量LSB（低表面亮度）星系的核晕模型的旋转曲线提出了一个新的简单解释。我们认为冷暗物质具有真正的无碰撞性质，即在相等和复合时期之间的小尺度上存在微弱的自相互作用，为此，我们假设了一个模型，其中强耦合重子辐射等离子体从小区域的冷暗物质中逸出而不失去平衡。利用经典动力学的变质量形式的Merscerskii方程，我们得到了关于CMB各向异性振荡与重子辐射等离子体喷射速度之间的关系的新结果，这些结果为研究CMB第二峰的数值计算提供了有用的工具.在此基础上，我们分别在Jeans理论和牛顿理论中讨论了这种弱自相互作用的冷暗物质中微扰的增长，得到了冷暗物质中分数微扰增长的表达式，该表达式简化为微扰理论在后期复合时期的标准结果.我们看到了冷暗物质势的平均扰动对宇宙微波背景温度各向异性的影响，这些各向异性起源于相等和复合之间的红移，即1100 < z < z_{eq}。我们还得到了Sachs-Wolfe效应的一个表达式，即在冷暗物质势的平均扰动下，在去耦时CMB温度各向异性。
