Voids in Open Universes

Abstract

The universe may be open and its galaxies may be distributed on spherical shells around the large scale voids that are detected in redshift surveys. To account for both features at once, we devise and present a new inflationary model that harbors two episodes of phase transitions. Of these transitions the former nucleates super-horizon-sized bubbles, which are seen from inside as open universes, while the latter generates a distribution of sub-horizon voids, of sizes typically around 10–100 Mpc/h, inside the open universes. The model realizes this sequence along the same slow-rolling path, by modulating the energy difference between vacuum states. Thus, with one physical process, it is possible to reconcile inflation with the recent observations of a low Ω0 and to seed the present large scale voids.