English

Cuscuton Bounce

General Relativity and Quantum Cosmology 2018-11-26 v2 High Energy Physics - Theory

Abstract

In general relativity producing a regular bounce entails violation of Null Energy Condition for a dynamical source in the model. That generically indicates existence of ghosts or other instabilities. However, in cuscuton modification of gravity, the correspondence between a background bounce and violation of Null Energy Condition for dynamical sources is broken. Cuscuton is an Infra Red modification and it can make the background go through a regular bounce. At the same time, since it does not contain any dynamical degrees of freedom, it does not lead to ghosts or other instabilities. Here, we present a toy scenario of a regular bouncing cosmology and prove this claim. Our model is presented as a proof of concept at this point and does not aim to explain observations in late time cosmology.

Keywords

Cite

@article{arxiv.1802.06818,
  title  = {Cuscuton Bounce},
  author = {Supranta S. Boruah and Hyung J. Kim and Michael Rouben and Ghazal Geshnizjani},
  journal= {arXiv preprint arXiv:1802.06818},
  year   = {2018}
}

Comments

16 pages, 8 figures

R2 v1 2026-06-23T00:26:52.259Z