Effective dark energy models and dark energy models with bounce in frames of F(T) gravity

Abstract

Various cosmological models in frames of F (T ) gravity are considered. The general scheme of constructing effective dark energy models with various evolution is presented. It is showed that these models in principle are compatible with ΛCDM model. The dynamics of universe governed by F (T ) gravity can mimics ΛCDM evolution in past but declines from it in a future. We also construct some dark energy models with the "real" (non-effective) equation-of-state parameter w such that w ≤ −1. It is showed that in F (T ) gravity the Universe filled phantom field not necessarily ends its existence in singularity. There are two possible mechanisms permitting the final singularity. Firstly due to the nonlinear dependence between energy density and H 2 (H is the Hubble parameter) the universe can expands not so fast as in the general relativity and in fact Little Rip regime take place instead Big Rip. We also considered the models with possible bounce in future. In these models the universe expansion can mimics the dynamics with future singularity but due to bounce in future universe begin contracts.

Inhomogeneous Dark Fluid and Dark Matter, Leading to a Bounce Cosmology

“…We take the interaction term Q to have the same form (37) as before. Solving the gravitational equation of motion (36) for dark matter, we find…”

“…Recently the F (R) and F (T ) gravity models in the presence of a bounce cosmology were discussed in Refs. [35][36][37][38][39]. We will in the following study similar bounce cosmologies.…”

Einstein–Cartan gravitational collapse of a homogeneous Weyssenhoff fluid

“…It is worth mentioning that, besides the model presented here, non-singular scenarios have been reported within models of f (R) theories of gravity in Palatini [171] and metric [172] formalisms, generalized teleparallel theories of gravity [173][174][175][176], bouncing in brane models [177][178][179][180][181] and modified Gauss-Bonnet gravity [182] (see also [183] for recent review). In [184], it is shown that a quantized neutral scalar field minimally coupled to classical gravitational field may avoid the singularity.…”

Bounce universe induced by an inhomogeneous dark fluid coupled with dark matter

“…Recently the F (R) and F (T ) gravity models in the presence of bounce cosmology was discussed in Refs. [26,27]. We will in the following study similar bounce cosmologies.…”