Iv. Tyutin et Ss. Shakhverdiev, SPACE-TIME LOCALITY IN THE SP(2)-SYMMETRICAL LAGRANGIAN-FORMALISM, Theoretical and mathematical physics, 115(3), 1998, pp. 658-669
The existence of a local solution to the Sp(2) master equation for the
gauge field theory is proved in the perturbation theory under standar
d regularity assumptions for the action. The arbitrariness of solution
s to the Sp(2) master equation is described, provided they are proper.
The effective action can be chosen to be Sp(2) invariant and (under t
he additional assumption that the gauge transformation generators are
Lorentz tensors) Lorentz invariant.