http://arxiv.org/abs/1711.10475
We explore exact cosmological solutions in nonlocal $f(T)$ gravity, where $T$ is the torsion scalar in teleparallel gravity. We derive effective forms of cosmological field equations describing the whole cosmic evolution history in a homogenous and isotropic cosmological background and construct the autonomous system of the first order dynamical equations. In addition, we investigate the local stability in the dynamical systems called “the stable/unstable manifold” by introducing a specific form of the interaction between matter, dark energy, radiation and a scalar field. Furthermore, we explore the exact solutions of the cosmological equations in the case of de Sitter spacetime. In particular, we examine the role of an auxiliary function called “gauge” $\eta$ in the formation of such cosmological solutions and show whether the de Sitter solutions can exist or not. Moreover, we study the stability issue of the de Sitter solutions both in vacuum and non-vacuum spacetimes. It is demonstrated that for nonlocal $f(T)$ gravity, the stable de Sitter solutions can be produced even in vacuum spacetime.
K. Bamba, D. Momeni and M. Ajmi
Thu, 30 Nov 17
53/77
Comments: 17 pages, 3 figures