Top: time evolution of the radial profiles of the surface density of planetesimals of r_p = 100 km when planetesimal fragmentation is considered with p = 5 / 3 and for a disk ten times more massive than the MMSN. Black dashed lines correspond to the isolated formation of a planet located at 5 au. Red solid lines correspond to the simultaneous formation of two planets located at 5 au and 6 au. The different lines correspond to different times: 0, 0.5, 1, 1.5, 2, and ~2.5 Myr. Eventually, the planetesimal surface density decreases in the neighborhood of both embryos. Bottom: same as top panel, but for fragments that most contribute into the total accretion rate, r_p ~ 25 km. In this case, the profiles increase around 5 au for t = 0.5,1,1.5 Myr, but for t = 2, ~2.5 Myr profiles decrease because of accretion. The increments in the surface density around 6 au correspond to the profiles at times 1.5, 2, and ~2.5 Myr. (Color version online.)