An explosive origin of bubbles in the distribution of galaxies?

Rather than involving any astrophysical development, the expansion of bubbles in a standard Friedmann-Lemaitre-Robertson-Walker universe is explored by onstraints on velocity and the redshifts corresponding to an explosive origin (sometime after decoupling) and freezing out. Cases of (a) constant velocity propagation and (b) geodesic expansion (as a limiting case) are considered for the Einstein-de Sitter, the high-density relativistic inflationary scenario, the low-density Milne, and the general pressure-free cosmological models. Plots of expected bubble sizes are provided. If the velocities are comparable to those produced by supernovae, difficulties arise in the high-density models in creating bubbles of sufficient diameter to match the observational data. However, geodesic expansion can explain the observed uniformity in maximum bubble size by showing insensitivity to the initial redshift. Although higher velocities produce larger bubbles, they are expected to destroy the uniformity. 15 references.