Light-like noncommutativity and duality from open strings/branes

In this paper we perform some non-trivial tests for the recently obtained open membrane/Dbrane metrics and ‘generalized’ noncommutativity parameters using Dp/NS5/M5-branes which have been deformed by light-like fields. The results obtained give further evidence that these open membrane/D-brane metrics and ‘generalized’ noncommutativity parameters are correct. Further, we use the open brane data and supergravity duals to obtain more information about non-gravitational theories with light-like noncommutativity, or ‘generalized’ light-like noncommutativity. In particular, we investigate various duality relations (strong coupling limits). In the light-like case we also comment on the relation between open membrane data (open membrane metric etc.) in six dimensions and open string data in five dimensions. Finally, we investigate the strong coupling limit (high energy limit) of five dimensional NCYM with Θ12 = Θ34. In particular, we find that this NCYM theory can be UV completed by a DLCQ compactification of M-theory.