arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.14477astro-ph.CO
收藏

用星系形状-形状关联度量中微子

Weighing the Neutrinos with the Galaxy Shape-Shape Correlations

Jounghun Lee, Suho Ryu

摘要:

星系的形成和演化在早期时代通过各向异性合并过程沿主窄丝,在其方向上,它们的形状变得细长和内在的对齐。宇宙网的非线性演化通过将初级细丝与多个次级细丝纠缠在一起而加宽了初级细丝,这具有降低合并过程的各向异性的效果,从而削弱了后期星系形状-形状的相关性。假设宇宙网络的非线性和复杂程度取决于暗物质的性质,我们提出了一个假设,即星系形状-形状关联函数$η(r)$可能是中微子总质量$M_ν$的有力补充探测器。测试这一假设对高分辨率N体模拟,我们表明,$η(r)$在$z=0$的$M_ν$依赖性是足够敏感的,以区分$M_ν=0.0$ eV和$M_ν=0.1$ eV。我们还表明,在$r\le 5\,h^{-1}$ Mpc之间的无质量和有质量的中微子模型之间的$η(r)$的差异,不能解释他们的小尺度密度功率,$σ_{8}$的差异,这意味着星系的形状形状关联函数有可能打破臭名昭著的宇宙退化之间的$M_ν$和$σ_{8}$。

英文摘要:

The galaxies form and evolve in the early epochs through the anisotropic merging process along the primary narrow filaments, in the direction of which their shapes become elongated and intrinsically aligned. The nonlinear evolution of the cosmic web broadens the primary filaments, by entangling them with multiple secondary filaments, which has an effect of reducing the anisotropy of the merging process and in consequence weakens the galaxy shape-shape correlations in the later epochs. Assuming that the degree of the nonlinearity and complexity of the cosmic web depends on the nature of dark matter, we propose a hypothesis that the galaxy shape-shape correlation function, $η(r)$, may be a powerful complimentary probe of the total neutrino mass, $M_ν$. Testing this hypothesis against a high resolution N-body simulation, we show that the $M_ν$-dependence of $η(r)$ at $z=0$ is sensitive enough to distinguish between $M_ν=0.0$ eV and $M_ν=0.1$ eV. We also show that the differences in $η(r)$ at $r\le 5\,h^{-1}$Mpc between the models with massless and massive neutrinos cannot be explained by their differences in the small-scale density powers, $σ_{8}$, which implies that the galaxy shape-shape correlation function has a potential to break the notorious cosmic degeneracy between $M_ν$ and $σ_{8}$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑