  The spin connection enters the theory of gravity as a nonabelian gauge field
associated with local Lorentz transformations. Normally it is eliminated from
making an extra assumption - that of the metricity of the vierbein field.
However, treated by itself with the usual gauge action, it has a negative beta
function, implying that it is asymptotically free. I suggest that the spin
connection could be confined (or perhaps partially confined) in the same way as
other nonabelian gauge fields. This would remove the need to make the extra
assumption of metricity, as the spin connection would not be present in the low
energy theory, leaving the symmetry to be realized only using metric variables.
