  Faddeev and Niemi have proposed a decomposition of SU(N) Yang-Mills theory in
terms of new variables, appropriate for describing the theory in the infrared
limit. We extend this method to SO(2N) Yang-Mills theory. We find that the
SO(2N) connection decomposes according to irreducible representations of SO(N).
The low energy limit of the decomposed theory is expected to describe
soliton-like configurations with nontrivial topological numbers. How the method
of decomposition generalizes for $SO(2N+1)$ Yang-Mills theory is also
discussed.
