2008/10/31 by Takeshi Kobayashi, Shinji Mukohyama · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.79.083501
published as Phys.Rev.D79:083501,2009 · 7 pages, REVTeX4, v2: published version
openalex publication_date 2009/04/02 · arxiv created 2009/04/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate density perturbations generated through modulated reheating while inflation is driven by a conformally coupled scalar field. A large running of the spectral index is obtained, which reflects the basic nature of conformal inflation that higher-order time derivatives of the Hubble parameter during inflation are not necessarily small. This feature may allow us to distinguish between conformal inflation models and standard minimally coupled ones. We also investigate how the resulting fluctuations are modified when there is a deviation from an exact conformal coupling between the inflaton and gravity. Finally, we apply our results to the warped brane inflation model and see that observational bounds from the WMAP5 data suggest a blue tilted density perturbation spectrum.