Evolution of the cosmological density distribution function
نویسنده
چکیده
We present a new calculation for the evolution of the 1-point Probability Distribution Function (PDF) of the cosmological density field based on an exact statistical treatment. Using the Chapman–Kolmogorov equation and second–order Eulerian perturbation theory we propagate the initial density distribution into the nonlinear regime. Our calculations yield the moment generating function, allowing a straightforward derivation of the skewness of the PDF to second order. We find a new dependency on the initial perturbation spectrum. We compare our results with other approximations to the 1-pt PDF, and with N-body simulations. We find that our distribution accurately models the evolution of the 1-pt PDF of dark matter.
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