  If bilayer graphene is placed in a high perpendicular magnetic field, several
quantum Hall plateaus are observed at low enough temperatures. Of these, the
$\sigma_{xy}=4ne^2/h$ sequence ($n\neq0$) is explained by standard Landau
quantization, while the other integer plateaus arise due to interactions. The
low-energy excitations in both cases are magnetoexcitons, whose dispersion
relation depends on single- and many-body effects in a complicated manner.
Analyzing the magnetoexciton modes in bilayer graphene, we find that the mixing
of different Landau level transitions not only renormalizes them, but
essentially changes their spectra and orbital character at finite wave length.
These predictions can be probed in inelastic light scattering experiments.
