Spherical Domain Wall Collapse in a Dust Universe

摘要: To clarify observational consequence of bubble nucleations in inflationary era, we analyse dynamics a spherical domain wall an expanding universe. We consider shell the with tension $\sigma$ collapsing spherically-symmetric dust universe, which is initially separated into open Friedmann-Lema\^itre-Robertson-Walker universe inside and Einstein-de Sitter outside. The collapses due to tension, sweeps fluid. after collapse becomes inhomogeneous described by Lema\^itre-Tolman-Bondi model. construct solutions describing this solving dynamical equations obtained from Israel's junction conditions applied system. find that black hole forms for any initial condition, mass at moment its formation universally given $M_{\rm BH}\simeq 17 \sigma/H_{\rm hc}$, where $H_{\rm hc}$ Hubble parameter time when radius equal radius. also fluid distributed as $\rho\propto R^{3/2}$ near central region collapse, $R$ area These features would provide observable signatures generated early