Parametrized path approach to vacuum decay

We develop a new real-time approach to vacuum decay based on a reduction to a finite number of degrees of freedom. The dynamics is followed by solving a generalized Schrödinger equation. We first apply this method to a real scalar field in Minkowski space and compare the decay rate with that obtained by the instanton approach. The main difference is in the early time dynamics, where the decay is faster due to the tail of the wave function. We then apply it to a cold atom model recently proposed to simulate vacuum decay experimentally. This approach will be extended to include gravity in a future work.