A New Angle on Gravitational Clustering
A New Angle on Gravitational Clustering
复制标题
引力聚类的新角度
DOI：
10.1111/j.1749-6632.2001.tb05618.x
复制
发表时间：
2000
影响因子：
5.2
通讯作者：
R. Scoccimarro
中科院分区：
文献类型：
--
作者：
R. Scoccimarro
文摘：描述了一种研究大尺度结构中引力不稳定性的新方法，其中运动方程像场论中那样用费曼图表示和求解。感兴趣的基本对象是传播子(它在时间上向前传播解)、顶点(描述波之间的非线性相互作用)和具有规定的统计信息的源，该源描述初始条件的影响。我们证明了回路修正使这些量重新正规化，并讨论了这一形式在更好地理解引力不稳定性和改进向非线性区域转变的非线性微扰理论方面的应用。我们还考虑了穿越壳层产生涡量的作用，并使用N体模拟表明，在小(维里化)尺度上，速度场达到均匀划分，即涡度功率谱大约是散度功率谱的两倍。
Abstract: A new approach to gravitational instability in large‐scale structure is described, where the equations of motion are written and solved as in field theory in terms of Feynman diagrams. The basic objects of interest are the propagator (which propagates solutions forward in time), the vertex (which describes nonlinear interactions between waves) and a source with prescribed statistics which describes the effect of initial conditions. We show that loop corrections renormalize these quantities, and discuss applications of this formalism to a better understanding of gravitational instability and to improving nonlinear perturbation theory in the transition to the nonlinear regime. We also consider the role of vorticity creation due to shell‐crossing and show using N‐body simulations for which at small (virialized) scales the velocity field reaches equipartition, that is, the vorticity power spectrum is about twice the divergence power spectrum.