Higher Derivative Gravity and Conformal Gravity From Bimetric and Partially Massless Bimetric Theory

Understand

In this paper we establish the correspondence between ghost-free bimetric theory and a class of higher derivative gravity actions, including conformal gravity and New Massive Gravity.

• We also characterize the relation between the respective equations of motion and classical solutions.
• We illustrate that, in this framework, the spin-2 ghost of higher derivative gravity is an artifact of the truncation to a 4-derivative theory.
• The analysis also gives a relation between the proposed partially massless (PM) bimetric theory and conformal gravity, showing, in particular, the equivalence of their equations of motion at the 4-derivative level.