Warm intermediate inflationary Universe model in the presence of a generalized Chaplygin gas

Abstract

A warm intermediate inflationary model in the context of generalized Chaplygin gas is investigated. We study this model in the weak and strong dissipative regimes, considering a generalized form of the dissipative coefficient = (T, φ), and we describe the inflationary dynamics in the slow-roll approximation. We find constraints on the parameters in our model considering the Planck 2015 data, together with the condition for warm inflation T > H , and the conditions for the weak and strong dissipative regimes.

Dynamics of warm power-law plateau inflation with a generalized inflaton decay rate: predictions and constraints after Planck 2015

“…The result of this analysis yields only a lower limit for C φ as well as for α and V 0 , given by C φ = 2.01 × 10 −12 , α = 1.5, and V 0 = 1.07 × 10 −12 , respectively. Just like the case a = 0, the case a = −1 has an interesting feature, because yields a strong dissipative dynamics compatible with observations, since that in previous works [52,53,[65][66][67][68][69], the inflaton decay rate ∝ φ 2 T is not able to describe a consistent strong dissipative dynamics.…”

“…φ 2 ) and a = 1 ( = C φ T ) have been studied extensively in the literature [38,43,47,[65][66][67][68][69]. During warm inflation, the energy density related to the scalar field predominates over the energy density of the radiation field, i.e., ρ φ ρ γ [33][34][35]56-61], but even if small when compared to the inflaton energy density it can be larger than the expansion rate with ρ 1/4 γ > H .…”

“…It is interesting that, for other inflaton potentials, the inflaton decay ratio a = 3 describes a consistent warm inflationary dynamics (see Refs. [43,47,[65][66][67][68][69]). Figure 1 shows the ratio /3H and the tensor-to-scalar ratio r as functions of the scalar spectral index n s for the case a = 1, i.e., (φ, T ) = C φ T .…”

Impact of generalized dissipative coefficient on warm inflationary dynamics in the light of latest Planck data

“…Moreover, many authors have investigated warm inflation in various alternative as well as modified theories of gravity [78][79][80][81][82]. Recently, Herrera et al [83] studied warm intermediate inflation in the context of GCG in the weak and strong dissipative regimes by assuming a generalized form of the dissipative coefficient under slow-roll approximation. They found the constraints on the parameters by considering the Planck 2015 data, together with the essential condition for warm inflation T > H .…”

Intermediate inflation in a generalized induced-gravity scenario

“…As mentioned previously, this inflation-ary model was originally studied in order to find an exact solution to the background equations. Nevertheless from the observational point of view, intermediate inflation is more effectively motivated in the slow-roll approximation [51][52][53][54][55][56][57][58][59][60]. Here, we consider the slow-roll approximation; it is feasible to find a scalar spectral index n s ∼ 1, and this kind of spectrum is favored by the current CMB data.…”