Constraints on braneworld inflation from CMB anisotropies

Shinji Tsujikawa*, Andrew R. Liddle

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)


We obtain observational constraints on Randall-Sundrum type II braneworld inflation using a compilation of data including WMAP, the 2dF and latest SDSS galaxy redshift surveys. We place constraints on three classes of inflation models (large-field, small-field and hybrid models) in the high-energy regime, which exhibit different behaviour compared to the low-energy case. The quartic potential is outside the 2σ observational contour bound for a number of e-folds less than 60, and steep inflation driven by an exponential potential is excluded because of its high tensor-to-scalar ratio. It is more difficult to strongly constrain small-field and hybrid models due to additional freedoms associated with the potentials, but we obtain upper bounds for the energy scale of inflation and the model parameters in certain cases. We also discuss possible ways to break the degeneracy of consistency relations and inflationary observables.

Original languageEnglish
Pages (from-to)1-21
Number of pages21
JournalJournal of Cosmology and Astroparticle Physics
Issue number3
Publication statusPublished - 2004 Mar
Externally publishedYes


  • CMBR theory
  • Cosmology with extra dimensions
  • Inflation
  • String theory and cosmology

ASJC Scopus subject areas

  • Astronomy and Astrophysics


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