Hidden Order in $URu_{2}Si_{2}$: The Need for a Dual Description
  Motivated by experiment, we argue that the enigmatic hidden order in $URu_2Si_2$ demands a dual description that encompasses both its itinerant and its local aspects. A combination of symmetry considerations and observation allow us to rule out a number of possibilities. The two remaining scenarios, the quadrupolar charge density wave and the orbital antiferromagnet, are discussed and experiments are suggested to select between these proposals. 
J. Mydosh, P. Chandra, P. Coleman and V. Tripathi