  Though commonly unrecognized, a superconducting BCS condensate consists of
equal numbers of two-electron (2e) and two-hole (2h) Cooper pairs (CPs). A
complete (in the sense that 2h-CPs are not ignored) boson-fermion statistical
model, however, is able to depart from this perfect 2e-/2h-CP symmetry and
yields robustly higher T_c's without abandoning electron-phonon dynamics. The
complete model reduces to all the known statistical theories of
superconductors, including the BCS-Bose "crossover" picture but going
considerably beyond it.
