VACUUM EXPECTATION VALUES FROM A VARIATIONAL APPROACH

In this letter we propose to use an extension of the variational appro ach known as Truncated Conformal Space to compute numerically the Vacu um Expectation Values of the operators of a conformal field theory per turbed by a relevant operator. As an example we estimate the VEV's of all (UV regular) primary operators of the Ising model and of some of t he Tricritical Ising Model when perturbed by any choice of relevant pr imary operators. We compare our results with some other independent pr edictions. (C) 1997 Elsevier Science B.V.