Criticality in the disordered $N$-color Ashkin-Teller model (opens in new tab)

The $N$-color Ashkin-Teller model corresponds to $N$ Ising models coupled by four-spin interactions. We consider the two-dimensional case in presence of quenched disorder and use scale invariant scattering theory to determine all the solutions of the exact renormalization group fixed points equations. The weak disorder sector is characterized by a solution that, for any fixed $N$ larger than 1, is a line of fixed points with Ising thermal expone...