Renormalizable and Unitary Lorentz Invariant Model of Quantum Gravity.

We analyze the R + R² model of quantum gravity where terms quadratic in the curvature tensor are added to the General Relativity action. This model was recently proved to be a selfconsistent quantum theory of gravitation, being both renormalizable and unitary. The model can be made practically indistinguishable from General Relativity at astrophysical and cosmological scales by the proper choice of parameters. [ABSTRACT FROM AUTHOR]