(a) Comparison between observed and simulated VDFs. Black circles show the observed VDF derived from SDSS field galaxies at 0.03 ≤ z ≤ 0.10 (Sohn et al. 2017a). Colored symbols display the simulated VDFs from five EAGLE simulations. Symbols are identical from Figure 5. (b) Same as (a), but the simulated VDFs are shifted by the σ_* offset determined based on the M_* − σ_* relations. Error bars on the solid lines indicate Poisson errors. For bins with fewer than ten galaxies, we only display the upper values, marked by arrows.