Original article at: http://www.math.washington.edu/~ejpecp/viewarticle.php?id=1935

Survival time of random walk in random environment among soft obstacles

Nina Gantert, University of Munster
Serguei Popov, Universidade de São Paulo
Marina Vachkovskaia, Universidade de Campinas

Abstract

We consider a Random Walk in Random Environment (RWRE) moving in an i.i.d. random field of obstacles. When the particle hits an obstacle, it disappears with a positive probability. We obtain quenched and annealed bounds on the tails of the survival time in the general d-dimensional case. We then consider a simplified one-dimensional model (where transition probabilities and obstacles are independent and the RWRE only moves to neighbour sites), and obtain finer results for the tail of the survival time. In addition, we study also the "mixed" probability measures (quenched with respect to the obstacles and annealed with respect to the transition probabilities and vice-versa) and give results for tails of the survival time with respect to these probability measures. Further, we apply the same methods to obtain bounds for the tails of hitting times of Branching Random Walks in Random Environment (BRWRE).

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Original article at: http://www.math.washington.edu/~ejpecp/viewarticle.php?id=1935