Year: 2019
Type: article
Abstract: A nonlocal gravity model based on $\frac{1}{\ensuremath{\square}}R$ achieves the phenomenological goals of generating cosmic acceleration without dark energy and suppressing the growth of perturbations compared to the $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model. Although the localized version of this model possesses a scalar ghost, the nonlocal version does not suffer from any obvious problem with ghosts. Here we study the possibility that the scalar ghost mode might be uncontrollably excited through time evolution, even though it is initially absent. We present strong evidence that this does not happen, so the analogy is with the conformal mode of general relativity which can be excited but only in a controlled way.
Authors: Sohyun Park, R. P. Woodard
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2889859780