Ising Model from Intertwiners

Understand

Spin networks appear in a number of areas, for instance in lattice gauge theories and in quantum gravity.

• They describe the contraction of intertwiners according to the underlying network.
• We show that a certain generating function of intertwiner contractions leads to the partition function of the 2d Ising model.
• This implies that the intertwiner model possesses a second order phase transition, thus leading to a continuum limit with propagating degrees of freedom.