String Theory Effective Action:. String Loop Corrections
Abstract
We discuss the general ideology of the computation of string loop corrections to the effective action for the massless modes of the string. Both the S-matrix and the sigma-model approaches are presented. It is emphasized that the effective action is a more general and better defined object than the S-matrix. In particular, it is finite in spite of modular infinities that may be present in loop amplitudes computed near a “wrong” vacuum. The case of the disc topology in the open-closed string theory is treated in some detail. Some issues concerning the soft dilaton vertex operators related to the infinities of the string amplitudes are disucssed.
- Publication:
-
International Journal of Modern Physics A
- Pub Date:
- 1988
- DOI:
- 10.1142/S0217751X88000138
- Bibcode:
- 1988IJMPA...3..365T