Statistical properties of the simulated cosmic overdensity field. Top: measured distribution of the δ_w overdensity field and the f_ln(δ_w, σ) lognormal distribution function for L = 60 Mpc h⁻¹ cubic windows in our ΛCDM and EdS simulations at z = 0 redshift. We plotted the Gaussian approximation of the density field as a dashed black curve. Bottom: measured σ² variance of the δ_w field as a function of the window volume at z = 0.