  It is generally believed that quantum oscillations are a hallmark of a Fermi
surface and the oscillations constitute the ringing of it. Recently, it was
understood that in order to have well defined quantum oscillations you do not
only not need well defined quasiparticles, but also the presence of a Fermi
surface is unnecessary. In this paper we investigate such a situation for an
inverted insulator from a analytical point of view. Even in the insulating
phase clear signatures of quantum oscillations are observable and we give a
fully analytical formula for the strongly modified Lifshitz-Kosevich amplitude
which applies in the clean as well as the disordered case at finite
temperatures.
