当前位置: X-MOL 学术J. Cosmol. Astropart. Phys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The two body problem in the presence of dark energy and modified gravity: application to the Local Group
Journal of Cosmology and Astroparticle Physics ( IF 5.3 ) Pub Date : 2020-09-29 , DOI: 10.1088/1475-7516/2020/09/056
M. McLeod , O. Lahav

We explore mass estimation of the Local Group via the use of the simple, dynamical `timing argument' in the context of a variety of theories of dark energy and modified gravity: a cosmological constant, a perfect fluid with constant equation of state $w$, quintessence (minimally coupled scalar field), MOND, and symmetrons (coupled scalar field). We explore generic coupled scalar field theories, with the symmetron model as an explicit example. We find that theories which attempt to eliminate dark matter by fitting rotation curves produce mass estimates in the timing argument which are not compatible with the luminous mass of the galaxies alone. Assuming that the galaxies are approaching their first encounter, MOND gives of around $2.7\times 10^{10} M_\odot$, roughly 10\% of the luminous mass of the LG, although a higher mass can be obtained in the case of a previous fly-by event between the MW and M31. The symmetron model suggests a mass too high to be explained without additional dark matter ($\mathcal{O}(10^{12}) M_\odot$), suggesting that there is a missing mass problem in this model. We also demonstrate that tensions in measurements of $H_0$ can produce an uncertainty in the Local Group mass estimate comparable to observational uncertainties on the separation and relative velocity of the galaxies, with values for the mass ranging from $4.5 - 5.4 \times 10^{12} M_{\odot}$ varying $h$ between 0.67 and 0.76.

中文翻译:

暗能量和修正引力存在下的二体问题:在Local Group中的应用

我们通过在各种暗能量和修正引力理论的背景下使用简单的动态“时间论证”来探索局部群的质量估计:宇宙常数,具有恒定状态方程 $w$ 的完美流体、quintessence(最小耦合标量场)、MOND 和对称子(耦合标量场)。我们探索了通用耦合标量场理论,以对称子模型作为一个明确的例子。我们发现试图通过拟合旋转曲线来消除暗物质的理论在时间参数中产生的质量估计与单独星系的光质量不兼容。假设星系正在接近它们的第一次相遇,MOND 给出大约 $2.7\times 10^{10} M_\odot$,大约是 LG 发光质量的 10\%,尽管在 MW 和 M31 之间的先前飞越事件的情况下可以获得更高的质量。对称子模型表明质量太高而无法在没有额外暗物质的情况下进行解释 ($\mathcal{O}(10^{12}) M_\odot$),表明该模型中存在质量缺失问题。我们还证明,$H_0$ 测量中的张力会在本地群质量估计中产生不确定性,与星系分离和相对速度的观测不确定性相当,质量值范围为 $4.5 - 5.4 \times 10^{ 12} M_{\odot}$ 在 0.67 和 0.76 之间变化 $h$。表明该模型中存在质量缺失问题。我们还证明,$H_0$ 测量中的张力会在本地群质量估计中产生不确定性,与星系分离和相对速度的观测不确定性相当,质量值范围为 $4.5 - 5.4 \times 10^{ 12} M_{\odot}$ 在 0.67 和 0.76 之间变化 $h$。表明该模型中存在质量缺失问题。我们还证明,$H_0$ 测量中的张力会在本地群质量估计中产生不确定性,与星系分离和相对速度的观测不确定性相当,质量值范围为 $4.5 - 5.4 \times 10^{ 12} M_{\odot}$ 在 0.67 和 0.76 之间变化 $h$。
更新日期:2020-09-29
down
wechat
bug