Approximating Density Probability Distribution Functions Across Cosmologies

Using a suite of self-similar cosmological simulations, we measure the probability distribution functions (PDFs) real-space density, redshift-space and their geometric mean. We find that density PDF is well-described by function two parameters: $n_s$, spectral slope, $\sigma_L$, linear rms fluctuation. For mean real- densities, introduce third parameter, $s_L={\sqrt{\langle(dv^L_{\rm pec}/dr)^2\rangle}}/{H}$. PDFs for LCDM cosmology also well-parameterized these three parameters. As result, are able to use simulations approximate range cosmologies. make publicly available provide an analytical fitting formula them.