Traverso's isogeny cutoff conjecture for p-divisible groups

Let $k$ be an algebraically closed field of characteristic $p>0$, let $H$ be a $p$-divisible group over $k$ of codimension $c$ and dimension $d$, and let $b_H$ be the smallest positive integer such that the isogeny class of $H$ is determined by its truncated group $H[p^{b_H}]$. Traverso's conjecture concerns this isogeny cutoff.

Traverso's isogeny cutoff conjecture. The isogeny cutoff satisfies

$$b_H\leq \left\lceil\frac{cd}{c+d}\right\rceil.$$

This conjecture gives a uniform bound, depending only on the codimension and dimension, for the amount of truncation needed to determine the isogeny class of a $p$-divisible group. The paper's abstract states that the authors prove the sharper formula $b_{c,d}=\left\lceil cd/(c+d)\right\rceil$, thereby proving Traverso's isogeny conjecture for $p$-divisible groups over $k$; the candidate itself is therefore solved.