%0 Journal Article
%T *-TREK: The One-Loop N=4 Noncommutative SYM Action
%A Hong Liu
%A Jeremy Michelson
%J Physics
%D 2000
%I arXiv
%R 10.1016/S0550-3213(01)00401-1
%X We investigate N=4 noncommutative super Yang-Mills (SYM) theory. We compute the one-loop four gauge boson scattering amplitude on parallel Dp-branes, and find the corresponding contribution to the noncommutative SYM one-loop action in a momentum expansion. The result is somewhat surprising. We find that while the planar diagram can be written using the usual *-product, the contributions from nonplanar diagrams in general involve additional structure beyond the *-product, arising from the nontrivial worldsheet correlations surviving the field theory limit. To each nonplanar diagram, depending on the number n of external vertex operator insertions on each boundary, there is a corresponding *_n n-ary operation. We further find that it is no longer possible to write down an off-shell gauge invariant one-loop effective action using the noncommutative field strength defined at tree-level.
%U http://arxiv.org/abs/hep-th/0008205v2