English

Non-perturbative unitarity and fictitious ghosts in quantum gravity

High Energy Physics - Theory 2020-11-20 v2 General Relativity and Quantum Cosmology

Abstract

We discuss aspects of non-perturbative unitarity in quantum field theory. The additional ghost degrees of freedom arising in "truncations" of an effective action at a finite order in derivatives could be fictitious degrees of freedom. Their contributions to the fully-dressed propagator -- the residues of the corresponding ghost-like poles -- vanish once all operators compatible with the symmetry of the theory are included in the effective action. These "fake ghosts" do not indicate a violation of unitarity.

Keywords

Cite

@article{arxiv.2009.06637,
  title  = {Non-perturbative unitarity and fictitious ghosts in quantum gravity},
  author = {Alessia Platania and Christof Wetterich},
  journal= {arXiv preprint arXiv:2009.06637},
  year   = {2020}
}

Comments

8 pages, 8 figures. V2: shortened version, matches the published one

R2 v1 2026-06-23T18:32:07.053Z