Introduction: Deformations

Deformations of a given classical SUGRA solution correspond to deformations of the 2d -model:

    

where is a small parameter and is a 2-form on the worldsheet, which is called integrated vertex operator.

Sometimes it is more convenient to study unintegrated vertices, which are obtained from integrated vertices by the descent procedure:

form degree
ghost number

The ghost number 2 object is called unintegrated vertex operator. It turns out that there is one to one correspondence . It is often more convenient to think about , because it is a scalar on the worldsheet.