A relativistic version of the Vlasov equation has recently been applie
d to the study of infinite nuclear matter, under the assumption that i
n hadronic matter the interaction are mediated by massive scalar and v
ector fields. The transverse small amplitude oscillations around a sta
tionary state are studied in the framework of that model. In particula
r, orthogonality and completeness relations for the transverse modes a
re obtained. The corresponding energy weighted sum rule is derived.