  A relative coordinate breathing mode in the quantum Hall system is predicted
to exist with different behavior under either Coulomb or dipole-dipole
interactions. While Kohn's theorem predicts that any relative coordinate
interaction will fail to alter the center of mass energy spectrum, it can
affect excitations in the relative coordinates. One such collective excitation,
which we call the hyperradial breathing mode, emerges naturally from a
few-body, hyperspherical representation of the problem and depends on the
inter-particle interactions, the ground state wave function, and the number of
particles participating in the excitation. Possible observations of this
excitation will be discussed in the context of both cold rotating atomic
simulations and conventional quantum Hall experiments.
