Dynamical interpretation of the wavefunction of the universe

In this paper, we study the physical meaning of the wavefunction of the universe. With the continuity equation derived from the Wheeler–DeWitt (WDW) equation in the minisuperspace model, we show that the quantity ρ(a)=|ψ(a)|2 for the universe is inversely proportional to the Hubble parameter of the universe. Thus, ρ(a) represents the probability density of the universe staying in the state a during its evolution, which we call the dynamical interpretation of the wavefunction of the universe. We demonstrate that the dynamical interpretation can predict the evolution laws of the universe in the classical limit as those given by the Friedmann equation. Furthermore, we show that the value of the operator ordering factor p in the WDW equation can be determined to be p=−2.