THE SCALING REGION OF THE TRICRITICAL ISING-MODEL IN 2 DIMENSIONS

We study the scaling region spanned by all four relevant perturbations of the tricritical Ising model in two dimensions. We analyze the spectrum of the (1 + 1)-dimensional off-critical hamiltonian on a truncated Hilbert space, a method recently proposed by Yurov and Al. Zamolodchikov. In the phase coexistence regions the massive excitations are kink states. On the temperature-driven two-phase coexistence line, they form bound states, which we analyze for periodic as well as for twisted boundary conditions. We find a new asymmetric two-phase region driven by the subleading magnetic field. There are some indications of massless states along the crossover line to the Ising model. The effects of off-critical integrability on the spectra are also observed and discussed.