Lorentz-violating gravity and the bootstrap procedure

Understand

In conventional gravitational physics, the so-called "bootstrap procedure" can be used to extrapolate from a linear model of a rank-2 tensor to a full non-linear theory of gravity (i.e., general relativity) via a coupling to the stress-energy of the model.

• In this work, I extend this procedure to a "Lorentz-violating" gravitational model, in which the linear tensor field and the matter fields "see" different metrics due to a coupling between the tensor field and a background vector field.
• The resulting model can be thought of as a generalized Proca theory with a non-minimal coupling to conventional matter.
• It has a similar linearized limit to the better-known "bumblebee model", but differs at higher orders in perturbation theory.