Comparison with exoplanets in the Kepler field (mass-period and radius-period diagrams). The left column shows the exoplanet population obtained by our simulation. The right plot shows the exoplanets found by Kepler (both candidates and confirmed). Top panel: planet mass (in M_⊕) vs. orbital period (in days). Bottom row: planet radius (in R_⊕) vs. period. For the simulated exoplanets, the radius was obtained with a conversion from the planet mass (see Appendix B).