Observing the Dimensionality of Our Parent Vacuum

Understand

It seems generic to have vacua with lower dimensionality than ours.

• We consider the possibility that the observable universe originated in a transition from one of these vacua.
• Such a universe has anisotropic spatial curvature.
• This may be directly observable through its late-time effects on the CMB if the last period of slow-roll inflation was not too long.