Fourier Transforms of Lorentz Invariant Functions
  Fourier transforms of Lorentz invariant functions in Minkowski space, with support on both the timelike and the spacelike domains are performed by means of direct integration. The cases of 1+1 and 1+2 dimensions are worked out in detail, and the results for 1+n dimensions are given. 
Alexander Wurm, Nurit Krausz, Cecile DeWitt-Morette and Marcus Berg