ANTI-DE SITTER ISLAND-UNIVERSES FROM 5D STANDING WAVES

We construct simple standing wave solutions in a 5D spacetime with a ghost-like scalar field. The nodes of these standing waves are islands of 4D anti-de Sitter spacetime. In the case of increasing (decreasing) warp factor, there are a finite (infinite) number of nodes and thus a finite (infinite) number of anti-de Sitter island-universes having different gravitational and cosmological constants. This is similar to the landscape models, which postulate a large number of universes with different parameters.