Coexisting vacua and effective gravity
arXiv:gr-qc/0503090 · doi:10.1016/j.physleta.2005.05.056
Abstract
Our Universe may be a domain separated by physical phase boundaries from other domain-Universes with different vacuum energy density and matter content. The coexistence of different quantum vacua is perhaps regulated by the exchange of global fermionic charges or by fermion zero modes on the phase boundary. An example would be a static de-Sitter Universe embedded in an asymptotically flat spacetime.
10 pages with elsart.cls; v3: published version in Einstein issue of PLA