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Khaled Saaidi

Khaled Saaidi

Academic rank: Professor
ORCID:
Education: PhD.
ScopusId: 4567832
HIndex:
Faculty: Faculty of Science
Address: Department of Physics, Faculty of Science, University of Kurdistan, Pasdaran Street, Sanandaj, Kurdistan, Iran. 2th Address: Science and Technology Park of Kurdistan, Buo Ali Boolvar, Ghane Square, Baharan Town , Sanandaj, Kurdistan, Iran.
Phone: 08733776900

Research

Title
Tachyon constant-roll inflation
Type
JournalPaper
Keywords
-
Year
2018
Journal PHYSICAL REVIEW D
DOI
Researchers Abolhassan Mohammadi ، Khaled Saaidi ، Tayeb Gol Anbari

Abstract

The constant-roll inflation is studied where the inflaton is taken as a tachyon field. Based on this approach, the second slow-roll parameter is taken as a constant which leads to a differential equation for the Hubble parameter. Finding an exact solution for the Hubble parameter is difficult and leads us to a numerical solution for the Hubble parameter. On the other hand, since in this formalism the slow-roll parameter η is constant and could not be assumed to be necessarily small, the perturbation parameters should be reconsidered again which, in turn, results in new terms appearing in the amplitude of scalar perturbations and the scalar spectral index. Utilizing the numerical solution for the Hubble parameter, we estimate the perturbation parameter at the horizon exit time and compare it with observational data. The results show that, for specific values of the constant parameter η, we could have an almost scale-invariant amplitude of scalar perturbations. Finally, the attractor behavior for the solution of the model is presented, and we determine that the feature could be properly satisfied.