{
  "id": "astro-ph/0406078",
  "version": "v2",
  "published": "2004-06-03T10:30:27.000Z",
  "updated": "2004-08-26T07:06:03.000Z",
  "title": "Observational constraints on braneworld inflation: the effect of a Gauss-Bonnet term",
  "authors": [
    "Shinji Tsujikawa",
    "M. Sami",
    "Roy Maartens"
  ],
  "comment": "10 pages, 10 figures, version to appear in Physical Review D",
  "journal": "Phys.Rev. D70 (2004) 063525",
  "doi": "10.1103/PhysRevD.70.063525",
  "categories": [
    "astro-ph",
    "gr-qc",
    "hep-ph",
    "hep-th"
  ],
  "abstract": "High-energy modifications to general relativity introduce changes to the perturbations generated during inflation, and the latest high-precision cosmological data can be used to place constraints on such modified inflation models. Recently it was shown that Randall-Sundrum type braneworld inflation leads to tighter constraints on quadratic and quartic potentials than in general relativity. We investigate how this changes with a Gauss-Bonnet correction term, which can be motivated by string theory. Randall-Sundrum models preserve the standard consistency relation between the tensor spectral index and the tensor-to-scalar ratio. The Gauss-Bonnet term breaks this relation, and also modifies the dynamics and perturbation amplitudes at high energies. We find that the Gauss-Bonnet term tends to soften the Randall-Sundrum constraints. The observational compatibility of the quadratic potential is strongly improved. For a broad range of energy scales, the quartic potential is rescued from marginal rejection. Steep inflation driven by an exponential potential is excluded in the Randall-Sundrum case, but the Gauss-Bonnet term leads to marginal compatibility for sufficient e-folds.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2004-08-26T07:06:03.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "98.80.Cq"
    ],
    "keywords": [
      "observational constraints",
      "quartic potential",
      "general relativity",
      "randall-sundrum type braneworld inflation",
      "gauss-bonnet term breaks"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Phys. Rev. D"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 651618
    }
  }
}