Random lasers are exotic light sources that emit coherent light without any of the confining mirrors that are part of a conventional laser.1, 2 Instead, the light inside a random laser is trapped by multiple scattering in a disordered medium and can thus be efficiently amplified. The downside is that random lasers emit their light at many different frequencies and in many different directions (...

We give a number of exact, analytical results for the stochastic dynamics of the density of local extrema (minima and maxima) of linear Langevin equations and solid-on-solid lattice growth models driven by spatially quenched random noise. Such models can describe nonequilibrium surface fluctuations in a spatially quenched random medium, diffusion in a random catalytic environment, and polymers ...

We consider catalytic branching random walk (the reactant) where the state space is a countable Abelean group. The branching is critical binary and the local branching rate is given by a catalytic medium. Here the medium is itself an autonomous (ordinary) branching random walk (the catalyst) – maybe with a different motion law. For persistent catalyst (transient motion) the reactant shows the u...

The spectral formulation of the stochastic nite element method (SSFEM) is applied to the problem of heat conduction in a random medium. Speciically, the conductivity of the medium, as well as its heat capacity are treated as uncorrelated random processes with spatial random uctuations. The paper introduces the basic concepts of the SSFEM using a simple one-dimensional heat conduction examples. ...