Nontrivial extension of Starobinsky inflation
Abstract
We consider a noncanonic field in the context of Starobinsky inflation. We work in Einsteinframe. In this frame, the gravitational part of the action is equivalent to the HilbertEinstein action, plus a scalar field called scalaron. We investigate a model with a heavy scalaron trapped at the effective potential minimum, where its fluctuations are negligible. To be more explicit, we consider a DiracBornInfeld (DBI) field, which is usually considered within the brane inflation context, as the noncanonic field. Although, the DBI field governs inflation through implicit dependence on Scalaron the boost factor, and other quantities are different from the standard DBI model. For appropriate parameters, this model is consistent with the Planck results.
 Publication:

Physics of the Dark Universe
 Pub Date:
 May 2021
 DOI:
 10.1016/j.dark.2021.100822
 arXiv:
 arXiv:2007.12176
 Bibcode:
 2021PDU....3200822K
 Keywords:

 Early universe;
 Inflation;
 F(R) theory;
 Starobinsky model;
 DiracBornInfeld(DBI) inflation;
 Brane inflation;
 Scalartensor;
 Multifield inflation;
 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 High Energy Physics  Theory
 EPrint:
 23 pages, 11 figures, Revised version