The figure shows multiple-planet systems discovered via the Doppler method and orbiting stars with estimated masses larger than 1.3 Msol. The left panel shows the published best-fit period ratio for the planetary systems. The right panel shows the planetary semi-major axes. The blue dashed line is the protoplanetary phase ice-line radius. We aim to conduct planet migration and planet-planet scattering simulations to probe the formation mechanisms of high-order MMR systems, eccentric multiple-planet systems, and circumprimary planets in close binary systems, which are currently poorly studied. These analyses will reveal the primordial planet-disk conditions needed to assemble the observed planetary architectures.
