Research Uncovers Uncertainties in Cosmological Phase Transitions

Recent research conducted by Huai-Ke Guo, Song Li, Yang Xiao, Jin Min Yang, and Yang Zhang has focused on the uncertainties associated with cosmological first-order phase transitions, particularly through numerical simulations of bubble nucleation. The paper, titled "Estimating the Uncertainty of Cosmological First Order Phase Transitions with Numerical Simulations of Bubble Nucleation," was submitted to arXiv on October 7, 2023, and has been revised as of September 2, 2024.

The study aims to validate analytical formulas used in calculating physical quantities related to vacuum bubbles. The authors performed several numerical simulations to identify potential systematic uncertainties. Key findings from the research include:

1. The simulated false vacuum fraction approaches the theoretical value as the simulated volume increases. Notably, when the cubic simulation volume exceeds a side length of 14.5 times the theoretical scale, results stabilize.
2. There is a discrepancy between the theoretical expected total number of bubbles and the simulated results, which may stem from inconsistent application of the false vacuum fraction formula.
3. Variations in nucleation rate prefactors have minimal impact on bubble kinetics.
4. The lifetime distribution in the sound shell model does not follow an exponential distribution, leading to a suppression in gravitational wave spectra.

These findings have implications for understanding the dynamics of phase transitions in cosmology and could influence future research in the field, particularly regarding gravitational wave detection and the behavior of vacuum bubbles in the early universe. The full paper can be accessed through arXiv at arXiv:2310.04654.