Ballistic L\'evy walk with rests: Escape from a bounded domain

Abstract

The L\'evy walk process for the lower interval of the time of flight distribution ($\alpha<1$) and with finite resting time between consecutive flights is discussed. The motion is restricted to a region bounded by two absorbing barriers and the escape process is analysed. By means of a Poisson equation, the total density, which includes both flying and resting phase, is derived and the first passage time properties determined: the mean first passage time appears proportional to the barrier position; moreover, the dependence of that quantity on $\alpha$ is established. Two limits emerge from the model: of short waiting time, that corresponds to L\'evy walks without rests, and long waiting time which exhibits properties of a L\'evy flights model. The similar quantities are derived for the case of a position-dependent waiting time. Then the mean first passage time rises with barrier position faster than for L\'evy flights model. The analytical results are compared with Monte Carlo trajectory simulations.