Particle approximations of Lyapunov exponents connected to Schrödinger operators and Feynman–Kac semigroups

We present an interacting particle system methodology for the numerical solving of the Lyapunov exponent of Feynman{Kac semigroups and for estimating the principal eigenvalue of Schrodinger generators. The continuous or discrete time models studied in this work consists of N interacting particles evolving in an environment with soft obstacles related to a potential function V. These models are related to genetic algorithms and Moran type particle schemes. Their choice is not unique. We will examine a class of models extending the hard obstacle model of K. Burdzy, R. Holyst and P. March and including the Moran type scheme presented by the authors in a previous work. We provide precise uniform estimates with respect to the time parameter and we analyze the fluctuations of continuous time particle models.