Construct an f (T )-theory from a bouncing FRW universe

Annotation: We show that the teleparallel f (T ) gravity can provide compatible versions of bouncing cosmologies. In this work two bounce universe models have been investigated. We present their phase portraits by constructing the phase space of the models. Also, the thermalization process of the universe during the bouncing period is discussed. We rewrite the solutions in Einstein frame to represent the torsion gravity as extra degree-offreedoms. The evolution of the equation-of-state of the torsion fluid has been studied. Assuming that the matter component to be a canonical scalar field, we obtain the scalar field potentials induced by the f (T ) gravity of the two suggested models. The evolution of the scalar field equation-of-state during bouncing period has been investigated. Moreover, we study the energy conditions of these two models. Finally, the slow roll validity in the bouncing cosmology is discussed.

Keywords: inflation, scalar field, teleparallel gravity