Massless flows from the coset model su(2)_k+1 otimes su(2)_k /su(2)_2k+1 to the minimal model M_k+2 are studied from the viewpoint of form factors. These flows include in particular the flow from the Tricritical Ising model to the Ising model. By analogy with the magnetization operator in the flow TIM -> IM, we construct all form factors of an operator that flows to Phi_1,2 in the IR. We make a numerical estimation of the difference of conformal weights between the UV and the IR thanks to the Delta-sum rule; the results are consistent with the conformal weight of the operator Phi_2,2 in the UV. By analogy with the energy operator in the flow TIM -> IM, we construct all form factors of an operator that flows to Phi_2,1. We propose to identify the operator in the UV with sigma_1Phi_1,2.
Download