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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
Warm Tachyon Inflation and Swampland Criteria
Type
JournalPaper
Keywords
Warm inflation , Tachyon scalar field , Slow-roll approximation , Swampland criterion
Year
2020
Journal Chinese Physics C
DOI
Researchers Abolhassan Mohammadi ، Tayeb Gol Anbari ، Haidar Shaikhahmadi ، Kosar sayar ، Laila Akhtari ، mariwan Ahmad rasheed ، Khaled Saaidi

Abstract

The scenario of two components warm tachyon inflation is considered where the tachyon field plays the role of inflaton and drives inflation. During inflation, the tachyon scalar field interacts with the other component of the Universe which is considered as photon gas, i.e. radiation. The interacting term contains a dissipation coefficient, and the study is modeled based on two different and familiar choices of the coefficient that have been studied in the literature. By applying the latest observational data, the acceptable ranges for the free parameters of the model are obtained. For any choice inside the estimated ranges, there is an acceptable concordance between the theoretical predictions and observations. Whereas the model is established based on some assumptions, it is vital to check their validity for the obtained values of the free parameters of the model. It is realized that the model is not self-consistent for all values of the ranges and sometimes the assumptions are violated. Therefore, to have both self-consistency and agreement with data the parameters of the model need to be constrained again. After that, we are going to consider the recently proposed swampland conjecture, which imposes two conditions on the inflationary models. These criteria could rule out some of the inflationary models, however, warm inflation is known as one of those models that could successfully satisfy the swampland criteria. A precise investigation determines that the proposed warm tachyon inflation could not satisfy the swampland criteria for some cases. In fact, for the first case of the dissipation coefficient, where there is dependency only on the scalar field, the model could agree with observational data, however, it is in direct tension with the swampland criteria. But, for the second case where the dissipation coefficient has a dependency on both scalar field and temperature, the model shows an acceptable agreement with observational data and it could properly satisfy the swampland criteria.