Strong approximation of time evolution operators for a finite system of oscillators with nonlinear coupling
H. Kröger · Journal of Mathematical Physics · 1985
We consider a system in three space dimensions consisting of a finite number of oscillators with a nonlinear interaction. Using projectors on N-particle subspaces of the Fock space, we show that the time evolution operator is strongly approximatable by exponentials of self-adjoint finite-rank operators (finite-dimensional Hermitian matrices), which can easily be calculated in the corresponding eigenrepresentation.