Anisotropies in Kaluza-Klein quantum cosmology Original Research Article

We study the behavior of anisotropies in the Bianchi IX universe with one extra dimension under the Hartle-Hawking boundary condition. The evolution of the metric components in imaginary time is presented paying special attention to the difference from those of the case without extra dimension. The evolution is confirmed to be generally more rapid when the extra dimension is present and this makes the region in mini-superspace where the wave function of the universe has significant value a little larger. The difference, however, brought about by the internal space is small. We find that the wave function has a non-trivial value for certain non-zero anisotropies even when they are relatively large. This implies that the primordial universe was anisotropic rather than isotropic.