Cosmological implications of the transition from the false vacuum to the true vacuum state

Abstract

We study cosmology with running dark energy. The energy density of dark energy is obtained from the quantum process of transition from the false vacuum state to the true vacuum state. We use the Breit–Wigner energy distribution function to model the quantum unstable systems and obtain the energy density of the dark energy parametrization rho _text {de}(t). We also use Krauss and Dent’s idea linking properties of the quantum mechanical decay of unstable states with the properties of the observed Universe. In the cosmological model with this parametrization there is an energy transfer between dark matter and dark energy. The intensity of this process, measured by a parameter alpha , distinguishes two scenarios. As the Universe starts from the false vacuum state, for the small value of alpha (0<alpha <0.4) it goes through an intermediate oscillatory (quantum) regime of the density of dark energy, while for alpha > 0.4 the density of the dark energy jumps down. In both cases the present value of the density of dark energy is reached. From a statistical analysis we find this model to be in good agreement with the astronomical data and practically indistinguishable from the Lambda CDM model.