  Let $E$ be the set of edges of the $d$-dimensional cubic lattice
$\mathbb{Z}^d$, with $d\geq2$, and let $t(e),e\in E$, be nonnegative values.
The passage time from a vertex $v$ to a vertex $w$ is defined as
$\inf_{\pi:v\rightarrow w}\sum_{e\in\pi}t(e)$, where the infimum is over all
paths $\pi$ from $v$ to $w$, and the sum is over all edges $e$ of $\pi$.
Benjamini, Kalai and Schramm [2] proved that if the $t(e)$'s are i.i.d.
two-valued positive random variables, the variance of the passage time from the
vertex 0 to a vertex $v$ is sublinear in the distance from 0 to $v$. This
result was extended to a large class of independent, continuously distributed
$t$-variables by Bena\"{\i}m and Rossignol [1]. We extend the result by
Benjamini, Kalai and Schramm in a very different direction, namely to a large
class of models where the $t(e)$'s are dependent. This class includes, among
other interesting cases, a model studied by Higuchi and Zhang [9], where the
passage time corresponds with the minimal number of sign changes in a
subcritical "Ising landscape."
