A Dark Energy Model Characterized by the Age of the Universe

Understand

Quantum mechanics together with general relativity leads to the K\'arolyh\'azy relation and a corresponding energy density of quantum fluctuations of space-time.

• Based on the energy density we propose a dark energy model, in which the age of the universe is introduced as the length measure.
• This dark energy is consistent with astronomical data if the unique numerical parameter in the dark energy model is taken to be a number of order one.
• The dark energy behaves like a cosmological constant at early time and drives the universe to an eternally accelerated expansion with power-law form at late time.