07.05.2009 (Thursday)

1/N corrections to gluon scattering in N=4 SYM and relation to N=8 supergravity

Regular Seminar Horatiu Nastase (RLNR - Tokyo)

at:
14:00 QMW
room 410B
abstract:

Motivated by the BDS conjecture, we look at 1/N corrections to gluon amplitudes in N=4 SYM.Infrared divergences are analyzed in two formalisms, of Catani and of Sterman/Tejeda-Yeomans. I willanalyze the 1/N expansion of the IR divergences, and find some systematics, at 3-loops, and iterated to any number of loops. Then we observe that up to 2-loop we have an exact relation to graviton scattering in N=8 supergravity, with a simple interpretation in a 't Hooft-like picture, but the higher loop extrapolation is problematic. Finally, I discuss the transcendentality of amplitudes and Catani IR divergent operators