The paper studies Hamiltonian systems with a strong potential forcing
the solutions to oscillate on a very small time scale. In particular,
we are interested in the limit situation where the size epsilon of thi
s small time scale tends to zero but the velocity components remain os
cillating with an amplitude variation of the order O(1). The process o
f establishing an effective initial value problem for the limit positi
ons will be called homogenization of the Hamiltonian system. This prob
lem occurs in mechanics as the problem of realization of holonomic con
straints, as various singular limits in fluid flow problems, in plasma
physics as the problem of guiding center motion and in the simulation
of biomolecules as the so-called smoothing problem. We suggest the sy
stematic use of the notion of weak convergence in order to approach th
is problem. This methodology helps to establish unified and short proo
fs of many known results which throw light on the inherent structure o
f the problem. Moreover, we give a careful and critical review of the
literature.