Distributional Modes for Scalar Field Quantization
  We propose a mode-sum formalism for the quantization of the scalar field based on distributional modes, which are naturally associated with a slight modification of the standard plane-wave modes. We show that this formalism leads to the standard Rindler temperature result, and that these modes can be canonically defined on any Cauchy surface. 
Alfonso F. Agnew and Tevian Dray