Holographic dark energy cosmology with a new coupling function

An interacting holographic dark energy model is investigated by using the recent observations of supernovae, cosmic microwave background radiation, baryonic acoustic oscillations and observed Hubble parameters. In this work, we exchanged the coupling parameter xi from constant into a varying function of redshift following the parameterization introduced by Chevallier, Polarski and Linder. The best-fit values of the various parameters determined through chi-square function minimization technique show that non-zero values of the coupling parameter are possible, and the equation of state parameter for dark energy less than -1 is also possible. Then, our model explains properly the transition of deceleration phase of the universe to the acceleration. Besides, our model seems to resolve the cosmic coincidence problem.

Automated summary

In this study, an interacting holographic dark energy model was examined using recent observations, with the possibility of non-zero coupling parameter values and dark energy state equation parameters less than -1. The model effectively explains the transition from deceleration to acceleration in the universe, potentially resolving the cosmic coincidence problem.