arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1001.3152astro-ph.COastro-ph.HE
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第五种力III的结构形成:重子和暗物质的分离

Structure Formation by the Fifth Force III: Segregation of Baryons and Dark Matter

Baojiu Li, Hongsheng Zhao

摘要:

在本文中,我们提出的$N$体模拟的结果与标量场耦合不同的冷暗物质(CDM)和重子。选择标量场势和耦合函数,使得标量场在具有高CDM密度的区域中获得重质量,从而表现得像变色龙。我们着重讨论了标量场的存在如何影响非线性大尺度结构的形成,以及标量场与重子和CDM粒子的不同耦合如何导致这两种物质在大尺度上和维里化晕内部的不同分布和演化.正如预期的那样,重子CDM分离在第五种力强的区域增加,而在致密区域几乎没有分离。我们还介绍了一种近似方法来识别维里化晕耦合标量场模型,考虑到标量场耦合,这是很容易实现的数字。研究发现,由于标量场的变色龙性质,使得晕的内部密度分布对环境的依赖性非常强。

英文摘要:

In this paper we present the results of $N$-body simulations with a scalar field coupled differently to cold dark matter (CDM) and baryons. The scalar field potential and coupling function are chosen such that the scalar field acquires a heavy mass in regions with high CDM density and thus behaves like a chameleon. We focus on how the existence of the scalar field affects the formation of nonlinear large-scale structure, and how the different couplings of the scalar field to baryons and CDM particles lead to different distributions and evolutions for these two matter species, both on large scales and inside virialized halos. As expected, the baryon-CDM segregation increases in regions where the fifth force is strong, and little segregation in dense regions. We also introduce an approximation method to identify the virialized halos in coupled scalar field models which takes into account the scalar field coupling and which is easy to implement numerically. It is find that the chameleon nature of the scalar field makes the internal density profiles of halos dependent on the environment in a very nontrivial way.

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。

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