  A matrix model of an asymptotically free theory with a bound state is solved
using a perturbative similarity renormalization group for hamiltonians. An
effective hamiltonian with a small width, calculated including the first three
terms in the perturbative expansion, is projected on a small set of effective
basis states. The resulting small hamiltonian matrix is diagonalized and the
exact bound state energy is obtained with accuracy of order 10%. Then, a brief
description and an elementary illustration are given for a related light-front
Fock space operator method which aims at carrying out analogous steps for
hamiltonians of QCD and other theories.
