Superrenormalizable quantum gravity with complex ghosts

TL;DR

This paper introduces a new class of superrenormalizable higher derivative quantum gravity models where unphysical states have complex poles, potentially ensuring unitarity despite the presence of ghosts.

Contribution

It proposes a novel approach to quantum gravity using complex ghost poles to maintain unitarity in superrenormalizable higher derivative models.

Findings

Models with complex poles can be formulated as unitary.

Higher derivative terms can be designed to avoid physical ghosts.

The approach aligns with Lee-Wick quantization principles.

Abstract

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.