English

No Open or Flat Bouncing Cosmologies in Einstein Gravity

High Energy Physics - Theory 2015-01-26 v2 Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology

Abstract

We show that bouncing open or flat Friedmann-Robertson-Walker cosmologies are inconsistent with worldsheet string theory to first approximation. Specifically, the Virasoro constraint translates to the null energy condition in spacetime at leading order in the alpha-prime expansion. Thus one must go beyond minimally-coupled Einstein gravity in order to find bounce solutions.

Keywords

Cite

@article{arxiv.1501.04606,
  title  = {No Open or Flat Bouncing Cosmologies in Einstein Gravity},
  author = {Maulik K. Parikh},
  journal= {arXiv preprint arXiv:1501.04606},
  year   = {2015}
}

Comments

11 pages, LaTeX, discussion expanded and references added

R2 v1 2026-06-22T08:06:09.641Z