Vacuum structure, zero modes, and the effective potential in light-cone quantization

A Hamiltonian formalism for the calculation of the usual effective potential is presented in the context of scalar field theory. When applied in the context of light-cone quantization, we find contributions at ${\mathit{k}}^{+}$=0 which are missed by standard light-cone infrared regularizations. We present a (time-dependent) regularization of the Hamiltonian which correctly incorporates these contributions at the one-loop level. We briefly discuss the implications of these findings for the more general program of diagonalizing the light-cone Hamiltonian.