English

Inflation driven by q-de Sitter

General Physics 2018-10-09 v2 High Energy Physics - Theory

Abstract

We propose a generalised de Sitter scale factor for the cosmology of early and late time universe, including single scalar field is called as inflaton. This form of scale factor has a free parameter qq is called as nonextensivity parameter. When q=1q=1, the scale factor is de Sitter. This scale factor is an intermediate form between power-law and de Sitter. We study cosmology of such families. We show that both kinds of dark components, dark energy and dark matter simultaneously are described by this family of solutions. As a motivated idea, we investigate inflation in the framework of qq-de Sitter. We consider three types of scenarios for inflation. In a single inflation scenario, we observe that, inflation ended without any specific ending inflation ϕend\phi_{end}, the spectral index and the associated running of the spectral index are %ns12ϵ,αs0 n_\mathrm{s} - 1 \sim -2\epsilon, \quad \alpha_\mathrm{s} \equiv 0 . To end the inflation: we should have q=34q=\frac{3}{4}. We deduce that the inflation ends when the evolution of the scale factor is a(t)=e3/4(t)a (t) =e_ {3/4} (t) . With this scale factor there is no need to specify ϕend\phi_{end}. As an alternative to have inflation with ending point, We will study q-inflation model in the context of warm inflation. We propose two forms of damping term Γ\Gamma. In the first case when Γ=Γ0\Gamma=\Gamma_0, we show the scale invariant spectrum, (Harrison-Zeldovich spectrum, i.e. ns=1n_s=1) may be approximately presented by (q=910,  N=70q=\frac{9}{10},~~N=70). Also there is a range of values of RR and nsn_s which is compatible with the BICEP2 data where q=910q=\frac{9}{10}. In case Γ=Γ1V(ϕ)\Gamma=\Gamma_1V(\phi), it is observed that small values of a number of e-folds are assured for small values of qq parameter. For q=910q=\frac{9}{10} a range of values of RR and nsn_s is compatible with the BICEP2 data.

Keywords

Cite

@article{arxiv.1409.3200,
  title  = {Inflation driven by q-de Sitter},
  author = {M. R. Setare and D. Momeni and V. Kamali and R. Myrzakulov},
  journal= {arXiv preprint arXiv:1409.3200},
  year   = {2018}
}

Comments

Version has been accepted for publication in "International Journal of Theoretical Physics", Titled changed

R2 v1 2026-06-22T05:53:48.254Z