Superrenormalizable quantum gravity with complex ghosts

Understand

We suggest and briefly review a new sort of superrenormalizable models of higher derivative quantum gravity.

• The higher derivative terms in the action can be introduced in such a way that all the unphysical massive states have complex poles.
• According to the literature on Lee-Wick quantization, in this case the theory can be formulated as unitary, since all massive ghosts-like degrees of freedom are unstable.