This paper presents the results of collisional evolution calculations for the Kuiper belt starting from an initial size distribution similar to that produced by accretion simulations of that region - a steep power-law large object size distribution that breaks to a shallower slope at r \sim 1 - 2 km , with collisional equilibrium achieved for objects r \lesssim 0.5 km .
We find that the break from the steep large object power-law causes a divot , or depletion of objects at r \sim 10 - 20 km , which in-turn greatly reduces the disruption rate of objects with r \gtrsim 25 - 50 km , preserving the steep power-law behavior for objects at this size .
Our calculations demonstrate that the roll-over observed in the Kuiper belt size distribution is naturally explained as an edge of a divot in the size distribution ; the radius at which the size distribution transitions away from the power-law , and the shape of the divot from our simulations are consistent with the size of the observed roll-over , and size distribution for smaller bodies .
Both the kink radius and the radius of the divot center depend on the strength scaling law in the gravity regime for Kuiper belt objects .
These simulations suggest that the sky density of r \sim 1 km objects is \sim 10 ^ { 6 } -10 ^ { 7 } objects per square degree .
A detection of the divot in the size distribution would provide a measure of the strength of large Kuiper belt objects , and constrain the shape of the size distribution at the end of accretion in the Kuiper belt .