In recent years the idea from Physics that the space contains energy whose gravitational effect approximates to Einstein's cosmological constant A, is termed as dark energy or quintessence. Dark energy could be dynamical, and its density is evolving to its natural value, zero, and is small since the expanding universe is old. In the present paper the dark energy is phantom energy for which the dominant energy condition is violated has been studied. It has been also noticed that when the size increases with time it becomes much remarkable and here a scenario has been examined where the big-rip can be circumvented as the time machines that shortcut the big-rip singularity.
Variable cosmology, Dark energy, Dark matter
