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

Lung-Yih Chiang

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

Lung-Yih Chiang

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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.

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Lung-Yih Chiang. 2005-08-17. Non-linearity of large-scale structure formation in the Universe. https://arxiv.org/abs/astro-ph/0508375

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