Capturing targetspace dynamics on the worldsheet

General facts about string theory:
  • Both kinematics and dynamics of the space-time follow from some simple properties of 2D sigma-model

  • The target space of this sigma-model is identified with the space-time; the space-times fields, such as gravity, are identified with the coupling constants of the sigma-model

  • The “simple properties” can be either classical or quantum or both; in any case, they should imply the equations of motion of the space-time fields

  • String theory predicts the existence of the infinite tower of massive particles, with the mass of the order Planck scale, which are essentially unobservable experimentally

However, the precise form of these principles has not yet been worked out, even until now!

Conceptually the simplest form of string theory, the theory of bosonic strings, is poorly understood at the level of dynamics.

For the superstrings, the formulation of basic postulates turns out to be tricky. There are two variants of them:
  1. NSR formalism

  2. Berkovits formalism

We will concentrate on the Berkovits formalism for Type IIB SUGRA.