Ghosts in classes of non-local gravity
arXiv:1412.1575 · doi:10.1016/j.physletb.2015.02.045
Abstract
We consider a class of non-local gravity theories where the Lagrangian is a function of powers of the inverse d'Alembertian operator acting on the Ricci scalar. We take an approach in which the non-local Lagrangian is made local by introducing auxiliary scalar fields, and study the degrees of freedom of the localized Lagrangian. We find that among the auxiliary scalar fields introduced, some of them are always ghost-like. That is, in the Einstein frame they develop a negative kinetic term. Because of this, except for a particular case already known in the literature, in general, it is not clear how to quantize these models and how to interpret this theory in the light of standard field theory.
13 pages
References in corpus (25)
- Nonlocal Cosmology
- Modified non-local-F(R) gravity as the key for the inflation and dark energy
- Cosmological perturbations and structure formation in nonlocal infrared modifications of general relativity
- Non-local gravity and dark energy
- Towards a Resolution of the Cosmological Singularity in Non-local Higher Derivative Theories of Gravity
- Dynamics of Nonlocal Cosmology
- Accelerating cosmologies from non-local higher-derivative gravity
- Phantom and non-phantom dark energy: The cosmological relevance of non-locally corrected gravity
- Localization of nonlocal theories
- Reconstructing the Distortion Function for Nonlocal Cosmology
- Nonlocal Models of Cosmic Acceleration
- Newtonian limit of nonlocal cosmology
- A non-local theory of massive gravity
- Screening of cosmological constant in non-local gravity
- Dynamics in Nonlocal Cosmological Models Derived from String Field Theory
- Screening of cosmological constant in non-local cosmology
- Nonlinear structure formation in Nonlocal Gravity
- Apparent ghosts and spurious degrees of freedom in non-local theories
- One-loop effective action for non-local modified Gauss-Bonnet gravity in de Sitter space
- Spherically symmetric static solutions in a non-local infrared modification of General Relativity
- Comments on scalar-tensor representation of nonlocally corrected gravity
- Screening of cosmological constant for De Sitter Universe in non-local gravity, phantom-divide crossing and finite-time future singularities
- Non-Local Gravity from Hamiltonian Point of View
- Stability analysis in Modified Non-Local Gravity
- A modified model of non-locally corrected gravity: Cosmology and the Newtonian limit
Cited by in corpus (9)
- Teleparallel Gravity: From Theory to Cosmology
- Invariant slow-roll parameters in scalar-tensor theories
- Post-Newtonian parameter for multiscalar-tensor gravity with a general potential
- Acausality in Nonlocal Gravity Theory
- Noether symmetry in a nonlocal f(T) Gravity
- Do the Spirits Rise?
- Does nonlocal gravity yield divergent gravitational energy-momentum fluxes?
- Inflation in non-local hybrid metric-Palatini gravity
- Hamiltonian Analysis of Nonlocal F(R) Gravity Models