1211.3878 (Hiroyuki Kitamoto et al.)

Scheme dependence of quantum gravity on de Sitter background    [PDF]

Hiroyuki Kitamoto, Yoshihisa Kitazawa

We extend our investigation of the IR effects on the local dynamics of matter fields in quantum gravity. Specifically we clarify how the IR effects depend on the change of the quantization scheme: different parametrization of the metric and the matter field redefinition. An arbitrary choice of the parametrization of the metric and the matter field redefinition do not preserve the Lorentz invariance of the local dynamics. As for the effect of different parametrization of the metric alone, the Lorentz symmetry breaking term can be eliminated by shifting the background metric. In contrast, we cannot compensate the matter field redefinition dependence by such a way. The Lorentz invariance can be retained only when we adopt the specific matter field redefinitions where all dimensionless couplings become scale invariant at the classical level.

View original: http://arxiv.org/abs/1211.3878