Numerical Estimations of the Distribution of the Lifetime of Bubbles Emerging from First Order Cosmological Phase Transitions

Abstract

We present a mathematical framework to produce a numerical estimation to the distribution of the lifetime of bubbles emerging from first order cosmological phase transitions. In a precedent work, we have implemented the Sound Shell model to predict the power spectra of gravitational waves arising from the decay of scalar fields. The model depends on the lifetime distribution of bubbles before collision, which in turn depends on the transition rate $\beta$ and the speed of the bubble wall $v$. Empirical exponential laws were used to describe the lifetime distribution and the resultant power spectra. For detonations, the results show a good agreement with simulations where the bubbles have nucleated simultaneously with a mean separation distance. However, for deflagrations, the results show that the amplitude of gravitational waves is higher at longer wavelength than simultaneous nucleation, indicating the importance of having a more accurate description of the lifetime distribution of bubble lifetime.