Abstract :
We study a system of coincident D4- and image-branes with non-zero world-volume magnetic fields in the weak coupling limit. We show that the conditions for absence of tachyons in the spectrum coincide exactly with those found in [], in the low energy effective theory approach, for the system to preserve a image of the supersymmetries of the type IIA string theory vacuum. We present further evidence about the stability of the system by computing the lowest order interaction amplitude from both open and closed channels, thus verifying the no force condition as well as the supersymmetric character of the spectrum. A brief discussion of the low energy effective five-dimensional world-volume theory is given.
