Expectation values of local fields in the Bullough-Dodd model and integrable perturbed conformal field theories

Exact expectation values of the fields eaϕ in the Bullough-Dodd model are derived by adopting the “reflection relations” which involve the reflection S-matrix of the Liouville theory, as well as a special analyticity assumption. Using this result we propose explicit expressions for expectation values of all primary operators in the c < 1 minimal CFr perturbed by the operator φ1,2 or φ2,1. Some results concerning the φ1,5 perturbed minimal models are also presented.