On the supersymmetry and gauge structure of Matrix theory

Supersymmetric Ward identity for the low energy effective action in the sta ndard background gauge is derived for arbitrary trajectories of supergravit ons in Matrix theory. In our formalism, the quantum-corrected supersymmetry transformation laws of the supergravitons are directly identified in close d form, which exhibit an intricate interplay between supersymmetry and gaug e (BRST) symmetry. As an application, we explicitly compute the transformat ion laws for the source-probe configuration at 1-loop and confirm that supe rsymmetry fixes the form of the action completely, including the normalizat ion, to the lowest order in the derivative expansion. (C) 2000 Elsevier Sci ence B.V. All rights reserved.