Almost every discussion of non-perturbative effects in Yang-Mills theory mentions in passing that they work in the temporal gauge. Why is this the case?
A good example is the QCD vacuum. Almost every discussion uses the temporal gauge, although the discussion in a physical gauge, like the axial gauge, is much simpler and leads directly to a non-degenerate vacuum state.
So far, I wasn't able to make sense of the "reasons" I was able to find in the literature.
For example, Shifman in his book "Advanced topics in quantum field theory" writes:
To single out the relevant degree of freedom in the infinite-dimensional space of the gluon fields, it is necessary to proceed to the Hamiltonian formulation of Yang-Mills theory. This implies, of course, that the time component of the four-potential $A_\mu$ has to be gauged away, $A_0= 0$.