Warm-Polytropic Inflationary Universe Model

Abstract

In the present paper we study warm inflationary universe models in the context of a polytropic gas. We derive the characteristics of this model in slow-roll approximation and develop our model in two cases, 1-For a constant dissipative parameter Γ. 2-Γ as a function of scalar field φ. In these cases we will obtain exact solution for the scalar field and Hubble parameter. We will also obtain explicit expressions for the tensor-scalar ratio R, scalar spectrum index n s and its running α s , in slow-roll approximation.

A Cosmological Model Describing the Early Inflation, the Intermediate Decelerating Expansion, and the Late Accelerating Expansion of the Universe by a Quadratic Equation of State

“…In particular, it can account for an increase of the scale factor by about 29 orders of magnitude in less than 10 −42 s. It would be important to determine whether this equation of state can reproduce the observed primordial fluctuations and power spectrum. This problem has been considered recently in [92][93][94]. The conclusion of these works is that the polytropic equation of state represents a robust and interesting scenario to study the evolution of the universe.…”

Tachyon warm-intermediate inflation in the light of Planck data

“…Depending on the values of (b, c) we have: (I)-the situation in which the formula is This parametrization has been used for non-SUSY models [52,53]. Q5: (III)-the case where Γ = Γ 0 is a positive constant (hereafter Γ 0 -parametrization: see [30,32,33,[42][43][44][54][55][56]) which implies that the pair (b, c) in Eq. ( 9) is strictly equal to (0, 0) and finally (IV) we utilize the so called high temperature regime (hereafter Γ 1 -parametrization) in which we select (b, c) = (0, 1) and thus Γ ∝ T (see also [57]).…”

Thermodynamic descriptions of polytropic gas and its viscous type as dark energy candidates

“…In addition, some authors make use of the Polytropic equation of state to describe dark energy and thus the current phase of universe expansion as well as to study the thermodynamics of universe in various theories of gravity [46][47][48][49][50][51][52][53][54]. More studies, including the numerous properties of a universe in which the Polytropic gas and its various possible modified forms (as the candidates of dark energy) interact with dark matter can be found in [55][56][57][58][59][60][61][62][63][64].…”