Collective Modes in the Hidden Ordered Phase of URu2Si2

We examine the form of the collective modes expected for a spin-dependent orbital density wave phase of the Under screened Anderson Lattice Model, which has been proposed as describing the Hidden Ordered Phase of URu2Si2. We discuss the magnetic field dependence of the phase diagram and the magnetic nematicity that occurs be low the HO transition. We calculate the collective modes associated with the HO phase transition and discuss possible experimental consequences.