String Field Theory

Abstract

Although the methods of conformal field theory have given us a wealth of possible string vacuums and a framework in which to begin phenomenology, there are still severe deficiencies in this formulation. First, conformal field theory is necessarily a perturbative formulation. It is based on the first quantized string model propagating on various compactified manifolds. The problem is that the first quantized functional formulation [Eq. (1.2.1)] is based on the sum over conformally inequivalent Riemann manifolds of genus g, which yields a perturbative series of Feynman diagrams. The success of this formulation is that it yields a finite formulation of gravity interacting with quarks and leptons. However, its drawback is that millions of conformal field theories can be constructed using the methods presented in the previous chapters, and there is absolutely no concrete way in which to choose which, if any, of these millions of vacuums corresponds to our real world.