Studies in the d-density wave state in relation to the high-T(c) cuprate superconductors

The d-density wave (DDW) ordered state and a state with coexisting DDW and the d-wave superconductivity (DSC) are studied in some detail in relation to the pseudogap physics of the high- T_c cuprates. The spin-spin correlator, the superfluid density, and the Hall number are calculated. The nature of the angle-resolved photoemission spectra and the collective modes are elucidated. It is shown that, under appropriate assumptions, these calculations strengthen the identification of the pseudogap gap phase with static DDW order.