One-loop effective action in chiral Einstein-Cartan gravity

Abstract: In chiral Einstein-Cartan gravity, a new gauge fixing procedure is implemented recently, leading to a very economical perturbation expansion of the action. Using this formulation and the relevant gauge-fixing, we develop the ghost Lagrangian on an arbitrary Einstein background using the BRST formalism. The novelty is the appearance of a new term quadratic in the tetrad field. We next compute the heat-kernel coefficients and understand the divergences arising in the gravitational one-loop effective action. In our computation the arising heat kernel coefficients depend only on the self-dual part of the Weyl curvature. We make a comparison between our results and what has been obtained for metric GR.