Some all-order classical solutions in non-polynomial closed string field theory

Abstract

If a conformal field theory is perturbed by a nearly marginal operator of dimension ( 1 h, 1 h ), then, under certain conditions and for a certain value of the perturbing parameter, we get a new conformal field theory. Starting from a string field theory based on the original conformal field theory, we show how to construct a classical solution in this string field theory to all orders in h , which represents string field theory formulated around the perturbed conformal field theory. We also show that the equation of motion of string field theory forces us to have a time-dependent dilaton background of the form ax 0 to order h 3 , which compensates for the change in the central charge of the conformal field theory under the perturbation.