Stability and fluctuation modes of giant gravitons with NSNS B field

We study the stability of the giant gravitons in the string theory background with NSNS B field. We consider the perturbation of giant gravitons formed by a probe D$(8-p)$ brane in the background generated by D$(p-2)$-D$(p)$ branes for $2 \le p \le 5$. We use the quadratic approximation to the brane action to find the equations of motion. For $p=5$, giant graviton configurations are stable independent of the size of the brane. For $p \ne 5$, we calculated the range of the size of the brane where they are stable. We also present the mode frequencies explicitly for some special cases.