2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/207893We present a second order gravity action which consists of ordinary Einstein action augmented by a first-order, vector like, Chern-Simons quasi topological term.This theory is ghost-free and propagates a pure spin-2 mode. It is diffeomorphism invariant, although its local Lorentz invariance has been spontaneously broken.7, SB/F/192-92High Energy Physics - Theorytext