Runaway planetesimal growth
= Runaway planetesimal growth
{title2=$\dot M/M\propto M^{1/3}$}
A growth regime in which larger <planetesimals> have shorter fractional growth times. In a dispersion-dominated population with nearly mass-independent random speed and strong <gravitational focusing>, fixed material density gives $\dot M\propto M^{4/3}$. The displayed scaling is an illustrative limit, not a universal law once large bodies control the random velocities.