English

Tensor perturbations in high-curvature string backgrounds

General Relativity and Quantum Cosmology 2009-10-30 v1 High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

We derive a generalized equation for the evolution of tensor perturbations in a cosmological background, taking into account higher-curvature contributions and a tree-level coupling to the dilaton in the string frame. The equation is obtained by perturbing the gravi-dilaton string effective action, expanded up to first order in α\alpha'. The α\alpha' corrections can modify the low-energy perturbation spectrum, but the modifications are shown to be small when the background curvature keeps constant in the string frame.

Keywords

Cite

@article{arxiv.gr-qc/9704045,
  title  = {Tensor perturbations in high-curvature string backgrounds},
  author = {M. Gasperini},
  journal= {arXiv preprint arXiv:gr-qc/9704045},
  year   = {2009}
}

Comments

9 pages, REVTEX, three figures included using EPSFIG. An updated collection of papers on the pre-big bang scenario in string cosmology is a available at http://www.to.infn.it/teorici/gasperini