2024 : 11 : 21
Kourosh Nozari

Kourosh Nozari

Academic rank: Professor
ORCID: https://orcid.org/0000-0003-4368-5823
Education: PhD.
ScopusId: 9276301800
HIndex:
Faculty: Science
Address: Department of Theoretical Physics, Faculty of Basic Sciences, University of Mazandaran, P. O. Box 47416-95447, Babolsar, Iran
Phone: 01135302482

Research

Title
Dissipative quintessential cosmic inflation
Type
JournalPaper
Keywords
Cosmological inflation Dissipative quintessence Perturbations Observational data
Year
2024
Journal Physics of the Dark Universe
DOI
Researchers Kourosh Nozari ، fateme Rajabi ، Narges Rashidi Talouki

Abstract

In this paper we construct a dissipative quintessential cosmic inflation. For this purpose, we add a multiplicative dissipative term in the standard quintessence field Lagrangian. We consider the specific form of dissipation as the time integral including the Hubble parameter and an arbitrary function that describes the dissipative properties of the quintessential scalar field. Inflation parameters and observables are calculated under slow-roll approximations and a detailed calculation of the cosmological perturbations is performed in this setup. We consider different forms of potentials and calculate the scalar spectral index and tensor-to-scalar ratio for a constant as well as variable dissipation function. To check the reliability of this model, a numerical analysis on the model parameters space is done in confrontation with recent observational data. By comparing the results with observational joint datasets at 68% and 95% confidence levels, we obtain some constraints on the model parameters space, specially the dissipation factor with e-folds numbers 𝑁 = 55 and 𝑁 = 60. As some specific results, we show that the power-law potential with a constant dissipation factor and 𝑁 = 60 is mildly consistent with observational data in some restricted domains of the model parameter space with very small and negative dissipation factor and a negligible tensor-to-scalar ratio. But this case with 𝑁 = 55 is consistent with observation considerably. For power-law potential and variable dissipation factor as 𝑄 = 𝛼𝜙𝑛, the consistency with observation is also considerable with a reliable tensor-to-scalar ratio. The quadratic and quartic potentials with variable dissipation function as 𝑄 = 𝛼𝜙𝑛 are consistent with Planck2018 TT, TE, EE+lowE+lensing data at the 68% and 95% levels of confidence for some intervals of the parameter 𝑛.