Super inflation mechanism and dark energy in F ( T , T G ) $F(T,T_{G})$ gravity

Abstract

There are various mechanisms that explain both the inflationary epoch of the early universe and a unification of this epoch with the other stages of the universe. In this study, we show all the expansion history of the universe and transition among of them in a single form by using the theoretical framework of F (T , T G ) gravity in the context of the FRW (Friedmann-Robertson-Walker) universe. According to a particular model we obtain the unified solutions of the field equations. Without using any scalar field description we especially present the super inflation mechanism composed of three phase regions which describes the evolution of the early universe. The mechanism begins with a vacuum state and then follows a super accelerated period where there are two regions. The first continues in a quintessential field, and the second is a region where the radiation is created. Furthermore, we verified this inflationary mechanism by using the spectral index parameter and the scalar tensor ratio, i.e., n s , r, and calculated the ratio of radiation emergent from the quintessence field. This creation should be in a certain rate in the early universe otherwise we show that the universe cannot survive and continue to expand. Also, we have obtained a phantom solution of the model that shows two regions which are compatible with the recent cosmological observations. In one respect, it is observed that the late time expansion of the universe is similar to the early time inflation.

Super inflation mechanism and dark energy from a cosmological entropy perspective

“…Next, the GSLT inequality is obtained. The super inflation mechanism, which was proposed by Keskin [10], and dark energy are discussed in terms of the validity of the GSLT frame that we obtain. It is observed that the results coming from the GSLT analysis verify these cases (i.e.…”

“…1. When n → ∞ [10] the EOS parameter goes to w = −1 (due toḢ = 0) , which shows de Sitter type inflation. The general expression of the GSLT inequality given by Eq.…”

“…3 ) [7], quasi-de Sitter vacuum inflation w ∼ = −1 [8,9], or a unification of both types of the expansion [10] in F (T , T G ) gravity theory [11][12][13]. However, the early time inflation and the late time acceleration of the universe in a unified form could be observed in the literature [14][15][16].…”

Viable super inflation scenario from F(T) modified teleparallel gravity

“…For a general expression, Friedmann Eqs. ( 6), ( 7) can be re-constructed by using the following notation [16] A = 8π G( p e − ρ e w)…”

“…Hence, testing the inflation scenarios are made by measuring CMB anisotropies and by calculating useful two parameters coming from the two types of perturbations [6] which are related to metric perturbations: as mentioned above, the first is the scalar (curvaa e-mails: alikeskin039@gmail.com; a.ihsankeskin@sirnak.edu.tr ture) perturbations, P R , take on a task as producing the seeds which form the present universe, and the second is the tensor perturbations, P T , which are dubbed as gravitational waves of the early-universe. In the literature, under the slow-roll condition 1 it was developed many different inflation scenarios such as the chaotic inflation [7], the quintessential inflation [8], k-inflation [9], the Brane inflation [10,11], the warm inflation [12][13][14], the intermediate inflation [15], the super inflation [16] and so on.…”