The time-evolution of a Coulomb system

The two-dimensional Coulomb problem is examined from the point of view of a mapping onto a harmonic oscillator basis which is suitable for the introduction of a species of coherent state. These multispace coherent states are especially suitable for the discussion of the time-evolution of the system under the influence of a stochastic perturbation, and the method permits the deduction of explicit forms for the matrix elements of a general evolution operator in terms of parameters describing the perturbation.