  A field-theoretic formulation of the exponential-operator technique is
applied to a nonperturbative Hamiltonian eigenvalue problem in electrodynamics,
quantized in light-front coordinates. Specifically, we consider the
dressed-electron state, without positron contributions but with an unlimited
number of photons, and compute its anomalous magnetic moment. A simple
perturbative solution immediately yields the Schwinger result of \alpha/2\pi.
The nonperturbative solution, which requires numerical techniques, sums a
subset of corrections to all orders in \alpha\ and incorporates additional
physics.
