Detection of the BCS transition in a trapped Fermi gas

We investigate theoretically the quasiparticle properties of a trapped gas of fermionic atoms in both the normal and the superfluid phases. Our analysis, which accounts for the shell structure of the normal phase spectrum, shows that the single-particle response of the gas to a modulation of the trapping frequency should indicate the onset of superfluidity. The results are discussed in the context of current experiments on trapped Fermi gases.