A note on the dimensional regularization of the Standard Model coupled with quantum gravity

In flat space, gamma(5) and the epsilon tensor break the dimensionally continued Lorentz symmetry, but propagators have fully Lorentz invariant denominators. When the Standard Model is coupled with quantum gravity gamma(5) breaks the continued local Lorentz symmetry. I show how to deform the Einstein Lagrangian and gauge-fix the residual local Lorentz symmetry so that the propagators of the graviton, the ghosts and the BRST auxiliary fields have fully Lorentz invariant denominators. This makes the calculation of Feynman diagrams more efficient. (C) 2004 Elsevier B.V. All rights reserved.