Kuiper Belt evolution due to dynamical friction

In this paper we study the role of dynamical friction on the evolution of a population of large objects ($m>10^{22}$ g) at heliocentric distances $>70$ AU in the Kuiper Belt. We show that the already flat distribution of these objects must flatten further due to non-spherically symmetric distribution of matter in the Kuiper Belt. Moreover the dynamical drag, produced by dynamical friction, causes objects of masses $\geq 10^{24} g$ to lose angular momentum and to fall through more central regions in a timescale $\approx 10^9 yr$. This mechanism is able to transport inwards objects of the size of Pluto, supposing it was created beyond 50 AU, according to a Stern & Colwell's (1997b) suggestion.