| Full text | |
| Author(s): |
Gomez, Humberto
;
Mafra, Carlos R.
;
Schlotterer, Oliver
Total Authors: 3
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW D; v. 93, n. 4, p. 25-pg., 2016-02-24. |
| Abstract | |
The low-energy limit of the massless two-loop five-point amplitudes for both type IIA and type IIB superstrings is computed with the pure spinor formalism and its overall coefficient determined from first principles. For the type IIB theory, the five-graviton amplitude is found to be proportional to its tree-level counterpart at the corresponding order in alpha'. Their ratio ties in with expectations based on S-duality since it matches the same modular function E-5/2 which relates the two-loop and tree-level four-graviton amplitudes. For R-symmetry violating states, the ratio between tree-level and two-loop amplitudes at the same alpha'-order carries an additional factor of -3/5. Its S-duality origin can be traced back to a modular form derived from E-5/2. (AU) | |
| FAPESP's process: | 13/11409-7 - Twistors, Yang-Mills and Super-String theory |
| Grantee: | Humberto Gomez Zuñiga |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |