  Let $S$ be a set of $n$ sites in the plane, so that every site $s \in S$ has
an associated radius $r_s > 0$. Let $\mathcal{D}(S)$ be the disk intersection
graph defined by $S$, i.e., the graph with vertex set $S$ and an edge between
two distinct sites $s, t \in S$ if and only if the disks with centers $s$, $t$
and radii $r_s$, $r_t$ intersect.Our goal is to design data structures that
maintain the connectivity structure of $\mathcal{D}(S)$ as sites are inserted
and/or deleted in $S$.
