Fate of the Kaluza-Klein bubble - art. no. 024010

We numerically study classical time evolutions of Kaluza-Klein bubble space -time which has negative energy after a decay of vacuum. As the zero-energy Witten bubble space-time, where the bubble expands infinitely, the subsequ ent evolutions of the Brill-Horowitz momentarily static initial data show t hat the bubble will expand in terms of the area. At first glance, this resu lt may support the Corley-Jacobson conjecture that the bubble will expand f orever as well as Witten's bubble. The irregular signatures, however, can b e seen in the behavior of the lapse function in the maximal slicing gauge a nd the divergence of the Kretchman invariant. Since there is no appearance of the apparent horizon, we suspect the appearance of a naked singularity a s the final fate of this space-time.