Abstract:
We consider a homogeneous
continuous-time random walk (CTRW) on the lattice $\mathbb Z^{d}$,
$d=1,2,\dots$, which is a kind of random trap model in a
time-dependent (“dynamic”) environment. The waiting time
distribution is renewed at each jump, and is given by a general
probability density depending on a parameter $\eta>0$ such that the
average waiting time is finite for $\eta >1$ and infinite for $\eta
\in (0, 1]$. By applying analytic methods introduced in a previous
paper we prove that the asymptotics of the quenched CTRW and of its
annealed version are the same for all $\eta >0$ and $d\geq 1$. We
also exhibit explicit formulas for the correction term to the
quenched asymptotics. For the border-line case $\eta=1$ we find an
explicit expression for the annealed limiting distribution, which
is, to our knowledge, new.
Key words and phrases:continuous-time random walk, random traps, dynamic random environment, singular waiting time, random walk in quenched environment.