Knotty inflation and the dimensionality of spacetime
  We suggest a structure for the vacuum comprised of a network of tightly
knotted/linked flux tubes formed in a QCD-like cosmological phase transition
and show that such a network can drive cosmological inflation. As the network
can be topologically stable only in three space dimensions, this scenario
provides a dynamical explanation for the existence of exactly three large
spatial dimensions in our Universe.
