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Title: Origin of density fluctuations in extended inflation

Journal Article · · Physical Review, D (Particles Fields); (USA)
 [1];  [2];  [3]
  1. NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL (USA) Department of Astronomy and Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, IL (USA)
  2. NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL (USA)
  3. NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL (USA) Department of Astronomy and Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, IL (USA) Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, IL (USA)

We calculate both the curvature and isocurvature density fluctuations that arise due to quantum fluctuations in a simple model of extended inflation based upon the Jordan-Brans-Dicke theory. The curvature fluctuations that arise due to quantum fluctuations in the Brans-Dicke field in general have a non-scale-invariant spectrum and an amplitude that is cosmologically acceptable and interesting without having to tune any coupling constant to a very small value. The curvature perturbations that arise due to the Higgs field are subdominant. If there are other massless fields in the theory, e.g., an axion or an ilion, then isocurvature fluctuations arise in these fields too. Production of gravitational waves and the massless particles associated with excitations of the Brans-Dicke field are also discussed. Several attempts at more realistic models of extended inflation are also analyzed. The importance of the Einstein conformal frame in calculating curvature fluctuations is emphasized. When viewed in this frame, extended inflation closely resembles slow-rollover inflation with an exponential potential, and the usual formula for the amplitude of curvature perturbations applies directly.

OSTI ID:
6051416
Journal Information:
Physical Review, D (Particles Fields); (USA), Vol. 42:12; ISSN 0556-2821
Country of Publication:
United States
Language:
English