English

Do the Spirits Rise?

General Relativity and Quantum Cosmology 2019-01-16 v2 Cosmology and Nongalactic Astrophysics

Abstract

A nonlocal gravity model based on 1R\frac1{\square} R achieves the phenomenological goals of generating cosmic acceleration without dark energy and of suppressing the growth of perturbations compared to the Λ\LambdaCDM 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 excited through time evolution, even though it is initially absent. We present strong evidence that this does not happen.

Keywords

Cite

@article{arxiv.1809.06841,
  title  = {Do the Spirits Rise?},
  author = {Sohyun Park and R. P. Woodard},
  journal= {arXiv preprint arXiv:1809.06841},
  year   = {2019}
}

Comments

20 pages, 7 figures, v2: revised for publication

R2 v1 2026-06-23T04:10:28.986Z