On a Three-Dimensional Gravity Model with Higher Derivatives

The purpose of this work is to present a model for 3D massive gravity with topological and higher-derivative terms. Causality and unitarity are discussed at tree-level. Power-counting renormalizability is also contemplated.Comment: 9 pages, Latex, no figures; to be published in Gen. Rel. Gra

Scalar-QED \beta-functions near Planck's Scale

The Renormalization Group Flow Equations of the Scalar-QED model near Planck's scale are computed within the framework of the average effective action. Exact Flow Equations, corrected by Einstein Gravity, for the running self-interacting scalar coupling parameter and for the running v.e.v. of $\phi^* \phi$, are computed taking into account threshold effects. Analytic solutions are given in the infrared and ultraviolet limits.Comment: 19 pp, Latex; typos corrected and references added. To appear in the Int. J. Mod. Phys.