The late cosmic acceleration and the coincidence problem in Bianchi type I Universe

Abstract

In locally rotationally symmetric (LRS) Bianchi-I spacetime, we are considering a special kind of a scale factor, called the hybrid expansion law (HEL). The HEL provides a description of the transition from deceleration to cosmic acceleration. A non-minimal interaction between dark energy (DE) and dark matter (DM) allows to combine the transition from matter dominance to the era of the DE dominance with the transition from decelerated to accelerated expansion. In the proposed model, the linear interaction of the two components solves the coincidence problem of our present Universe. We present examples of numerical values of the HEL parameters compatible with the constructed model and the observational data.