全國中小學科展

宇宙演化的黑手

科展類別

臺灣國際科展

屆次

2007年

科別

地球與太空科學

學校名稱

國立臺灣師範大學附屬高級中學

指導老師

吳俊輝

作者

鍾岳霖

關鍵字

宇宙 演化

摘要或動機

We study the effect of dark energy on the evolution of cosmic structure in a scenario
where the dark energy is treated as free particles and thus can be localized. By
theoretical derivation and numerical simulations, we found that:

1. The dark energy particles gain kinetic energy from a moving dark matter particle
through gravitational interaction. Due to energy conservation, the dark matter particle
will slow down with time

Ek(t) = Ek0 - 9 × 10-5[|1+3w|ρDE]1.92t where Ek(t) is the kinetic energy of the dark matter particle,Ek0 is its initial kinetic energy, w is the coefficient of equation of state for dark
energy, ρDE is the mean energy density of dark energy, and t is the time.



2. The formation history and structure of galaxy clusters are different in the presence
of localized dark energy. The more the localized dark energy, the earlier the formation
of the cluster core. In addition, the kinetic energy Ek(R) as a function
of R will be different if the ρDE is different. Thus we can compare the
observed Ek(R) of clusters with our results to deduce the ρDE in our universe. The results here can be applied to the observations in the near
future.


我們探討宇宙結構演化受到可局部叢集之黑暗能量粒子的影響。藉由理論推導及電腦模擬,我們發現:

一、黑暗能量粒子會透過重力交互作而從運動中的黑暗物質粒子獲得力學能。因力學能守恆,黑暗物質粒子的速率會減慢,滿足


Ek(t) = Ek0 - 9 × 10-5[|1+3w|ρDE]1.92t

其中Ek(t) 為黑暗物質粒子的動能,Ek0 為其初始動能,w 為狀態方程式係數,ρDE 為黑暗能量的平均密度,t
為時間。



二、星系團的形成過程及結構,會因可局部叢集之黑暗能量的存在而改變。黑暗能量越多時,星系團的核心會越早形成。而且動能 Ek(R) 隨著至星系中心距離R
的變化,會因 ρDE 的不同而不同,因此可以將量測到的 Ek(R) 和這裡的結果比對,推導出宇宙中的 ρDE
。 這些研究成果將可直接應用在未來的觀測結果上。

宇宙演化的黑手

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