The torsion cosmology in Kaluza–Klein theory

Abstract

We have studied the torsion cosmology model in Kaluza-Klein theory. We considered two simple models in which the torsion vectors are Aµ = (α, 0, 0, 0) and Aµ = a(t) 2 (0, β, β, β), respectively. For the first model, the accelerating expansion of the Universe can be not explained without dark energy which is similar to that in the standard cosmology. But for the second model, we find that without dark energy the effect of torsion can give rise to the accelerating expansion of the universe and the alleviation of the well-known age problem of the three old objects for appropriated value of the model parameter β. These outstanding features of the second torsion cosmology model have been supported by the Type Ia supernovae (SNIa) data.

Power-law entropy-corrected holographic dark energy in Hořava-Lifshitz cosmology with Granda-Oliveros cut-off

“…Taking into account the above reasons, in the following calculations, we will neglect the derivatives of γ n and we will consider as expression for γ n the one obtained in Eq. (99).…”

“…Also in the interacting case, the expressions of γ n and γ ′ n are the same as the non-interacting case, given respectively in Eqs. (99) and (100). Instead, the expression of u ′ is given by:…”

“…we have G N (t); furthermore, they obtained that the EoS parameter ω D can be significantly modified when the low-redshift z limit is considered. Chen et al [99] studied the HDE model in order to obtain an inflationary epoch in the early evolutionary stages of our Universe. The HDE model was recently considered in other works with different IR cut-offs, for example the Hubble horizon, the particle horizon and the future event horizon [100][101][102][103][104][105].…”

Metric theory of gravity with torsion in an extra dimension

“…In the cosmology equations generated from those field equations, acceleration was not an independently prescribable initial condition. Chen and Jing [23] showed that those equations yield accelerating universe solutions without resorting to dark energy. They show that the model not only fits the supernovae data, but also solves the cosmic age problem of old high redshift objects [24].…”

Some non-linear interactions in polytropic gas cosmology: phase space analysis

“…Very soon it has been found that an interaction between the components of the universe can give desirable results, namely, can solve the cosmological coincidence problem and give appropriate behavior to the cosmological parameters. Considered forms of the interaction have phenomenological origin and mainly formed from the dimensional analysis (Guo, Z. K. et al 2005;Wei, H. et al 2006;Cai, R. G. et al 2005;Zhang, H. et al 2005;Wu, P. et al 2007;Chen, X. M. et al 2009;He, J. H. et al 2009;Chimento, L.P. 2009;Setare, M. R. 2006Setare, M. R. , 2007bJamil, M. et al 2008). It is not excluded that a fundamental theory explaining the origin of the interaction could be constructed when the nature of dark energy and dark matter will be established.…”