Light-Front Dynamics Of Massive Vector Chern-Simons Gravity

TL;DR

This paper introduces a ghost-free, diffeomorphism-invariant gravity theory with a Chern-Simons term, analyzing its properties using light-front coordinates and revealing solutions to its differential constraints.

Contribution

It develops a second order gravity action with a Chern-Simons term, performs light-front analysis, and solves differential constraints in quasi LF coordinates.

Findings

The theory propagates a pure spin-2 mode.

Differential constraints are solvable in quasi LF coordinates.

The model is ghost-free and exhibits spontaneous Lorentz symmetry breaking.

Abstract

We 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 spontaneuosly broken. We perform the light-front (LF) analysis for both the linearized system and the exact curved model. In constrast to the 2+1 canonical analysis, in the quasi LF coordinates the differential constraints can be solved. Its solution is presented here.