Removal of nonphysical states
We have seen that there are some unphysical deformations. One way to look at them is to consider the so-called beta deformation which is adding to the action the wedge product of two global symmetry currents:



The corresponding unintegrated vertex is . This is nonphysical when where is the structure constants of the global symmetry group (super-Poincare). Notice that:

Therefore, we must postulate that: