Abstract: |
We investigate the possibility of a new massive gravity theory with derivative interactions as an extension of de Rham-Gabadadze-Tolley massive gravity. We find the most general Lagrangian of derivative interactions whose cutoff energy scale is Lambda_3, which is consistent with de Rham-Gabadadze-Tolley massive gravity. Surprisingly, this infinite number of derivative interactions can be resummed with the same method in de Rham-Gabadadze-Tolley massive gravity, and remaining interactions contain only two parameters. We show that the equations of motion for scalar and tensor modes in the decoupling limit contain 4th derivatives with respect to space-time, which implies the appearance of ghosts at Lambda_3. We claim that consistent derivative interactions in de Rham-Gabadadze-Tolley massive gravity has a mass scale M, which is much smaller than the Planck mass. |