English

Non-linearity of large-scale structure formation in the Universe

Astrophysics 2007-05-23 v1

Abstract

In the standard picture of cosmological structure formation, the Universe we see today is evolved under the gravitational instability from tiny random fluctuations. In this talk I discuss the onset of non-linearity in the large scale structure formation of the Universe when the linear perturbation theory break downs. Using 1D Zel'dovich Approximation which provides an exact solution for density evolution, I illustrate two effects: mode spawning and mode merging and their connection to mode coupling. Those mode couplings (quadratic, cubic >...etc.) from gravitational clustering are in fact what the polyspectra (bispectrum, trispectrum...etc.) are meant to measure.

Keywords

Cite

@article{arxiv.astro-ph/0508375,
  title  = {Non-linearity of large-scale structure formation in the Universe},
  author = {Lung-Yih Chiang},
  journal= {arXiv preprint arXiv:astro-ph/0508375},
  year   = {2007}
}

Comments

talk in "Nonlinear Cosmology" workshop at ICTP, Trieste, May 2005. To appear in the special volume "Nonlinear Cosmology" of International J. of Modern Physics D