  SU(2) gauge theory coupled to massless fermions in the adjoint representation
is quantized in light-cone gauge by imposing the equal-time canonical algebra.
The theory is defined on a space-time cylinder with "twisted" boundary
conditions, periodic for one colour component (the diagonal 3- component) and
antiperiodic for the other two. The focus of the study is on the non-trivial
vacuum structure and the fermion condensate. It is shown that the
indefinite-metric quantization of free gauge bosons is not compatible with the
residual gauge symmetry of the interacting theory. A suitable quantization of
the unphysical modes of the gauge field is necessary in order to guarantee the
consistency of the subsidiary condition and allow the quantum representation of
the residual gauge symmetry of the classical Lagrangian: the 3-colour component
of the gauge field must be quantized in a space with an indefinite metric while
the other two components require a positive-definite metric. The contribution
of the latter to the free Hamiltonian becomes highly pathological in this
representation, but a larger portion of the interacting Hamiltonian can be
diagonalized, thus allowing perturbative calculations to be performed. The
vacuum is evaluated through second order in perturbation theory and this result
is used for an approximate determination of the fermion condensate.

High Energy Physics - Theory