We examine the spectrum of small vibrations of giant gravitons when the gravitons expand in anti–de Sitter space and when they expand on the sphere. For any given angular harmonic, the modes are found to have frequencies related to the curvature length scale of the background; these frequencies are independent of radius (and hence angular momentum) of the brane itself. This implies that the holographic dual theory must have, in a given R charge sector, low-lying non-BPS excitations with level spacings independent of the R charge.

• Received 12 September 2000

DOI:https://doi.org/10.1103/PhysRevD.63.024013