Gravitational waves from the vacuum decay with LISA *

Abstract We investigate the gravitational wave spectrum originating from cosmological first-order phase transition. compare two models: one is a scalar field model without gravitation, while other with gravitation. Based on sensitivity curves of LISA space-based interferometer stochastic gravitational-wave background, we difference between spectra former and latter cases obtained bubble collision process. In particular, numerically calculate speed wall before for models. demonstrate that amplitudes these can clearly distinguish expect Signal to Noise Ratio = 10 could observe as fast