How the huge energy of quantum vacuum gravitates to drive the slow accelerating expansion of the Universe

Understand

We investigate the gravitational property of the quantum vacuum by treating its large energy density predicted by quantum field theory seriously and assuming that it does gravitate to obey the equivalence principle of general relativity.

• We find that the quantum vacuum would gravitate differently from what people previously thought.
• The consequence of this difference is an accelerating universe with a small Hubble expansion rate $H\propto \Lambda e^{-\beta\sqrt{G}\Lambda}\to 0$ instead of the previous prediction $H=\sqrt{8\pi G\rho^{vac}/3}\propto\sqrt{G}\Lambda^2\to\infty$ which was unbounded, as the high energy cutoff $\Lambda$ is taken to infinity.
• In this sense, at least the "old" cosmological constant problem would be resolved.