Interacting Holographic Dark Energy, the Present Accelerated Expansion and Black Holes

We study the evolution of the universe by assuming an integrated model, which involves interacting dark energy and the holographic principle with the Hubble scale as an IR cutoff. First we determine the interaction rate at which matter is converting to dark energy. At the next step, we evaluate the equation of state parameter which describes the nature of dark energy. Our result predicts that the present state of the universe is dominated by quintessence type dark energy, and it will become phantom dominated in the near future. Again, our analysis successfully addresses the problem of present accelerated expansion of the universe and softens the coincidence problem. We also find that the universe was previously undergoing a decelerated phase of expansion and a transition from deceleration to acceleration should have occurred at a time t(q=0) = 0.732t(0), where t(0) is the present age of the universe. Finally, we discuss the evolution of black holes in this environment.