Non-Linear Theory of Gravitational Instability in the Expanding Universe
Non-Linear Theory of Gravitational Instability in the Expanding Universe
复制标题
膨胀宇宙中引力不稳定的非线性理论
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
K. Tomita
中科院分区：
文献类型：
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作者：
K. Tomita
首先指出，在宇宙膨胀的辐射主导阶段，与一阶转动波和引力波最自然相关的二阶密度波的演化应区分为两种方式，并对孤立涡旋的行为与周期性分布涡旋的行为进行了比较。其次，分析了在中间阶段（退耦时刻tD前后）与转动波、密度波及其混合波有关的二阶波，并计算了在tD后不久由于惯性力引起的压缩的快度。最后在上述分析的基础上探讨了星系形成的可能性。此外，由于非线性过程的级联形成相对较小的星系的可能性被认为是。
First it is indicated that, at the radiation-dominated stage of the expanding universe, two ways should be distinguished for the evolution of the second-order density waves most naturally associated with the first-order rotational and gravitational waves, and the behavior of an isolated eddy is examined for a comparison with those of periodically distributed eddies. Next the second-order waves associated with rotational, density and their mixed waves at the intermediate stage (before and after the decoupling epoch tD) are analyzed and the rapidity of compression due to the inertial force appearing soon after tD is calculated. Finally the possibility of galaxy formation is examined on the basis of the above analysis. Moreover a possibility for comparatively small galaxies to be formed through the cascade due to non-linear process is considered.