  We propose new variables of Faddeev-Niemi type for static SU(3) Yang-Mills
theory. These variables reveal a structure of a nonlinear sigma model, whose
field variables are two chiral fields taking values in SU(3)/(U(1)xU(1)) and
SU(3)/(SU(2)xU(1)). The nonlinear sigma model was introduced by Faddeev and
Niemi as a natural extension of the Faddeev chiral model. Shabanov showed that
the energy functional of the extended model is bounded from below by a
topological invariant, and therefore may support knot-like excitations and a
mass gap.
