Speaker
Hirohiko Shimada
(NIT Tsuyama)
Description
Consider M copies of the q-state Potts models and the O(n) models coupled through the bond-bond interaction. Non-trivial IR fixed points exist both in the disordered model (the replica limit $M \to 0$) and in the unitary model (such as q=3 with M=3, 4, 5, ...).
Conformal perturbation theory yields the critical exponents in the expansions in (q-2) or (1-n) around the M-coupled Ising CFTs in 2d, where the coupling is marginal. In addition, the RG flow generated by the Zamolodchikov C-function extracted from the transfer matrix can capture non-perturbative multicritical fixed points at M=0. The S-matrix and Monte Carlo method may also be used to explore the theory space. We also discuss some basic known results for M>2.