Abstract:

I will begin with a discussion of particle-hole asymmetry in doped Mott  insulators and exact sum rules for one-particle spectroscopies. I will then turn to a variational approach to gain insight into the strongly correlated d-wave superconducting state of the high Tc cuprates. After a quick review of earlier work on the essential difference between pairing and phase  coherence in doped Mott insulators, I will describe new results. These include: the notion of the "underlying" Fermi surface in the SC state;  doping and temperature dependence of the superfluid density and the insensitivity of the strongly correlated superconducting state to disorder.