On the Lorentz invariance of the Square root Klein-Gordon Equation
  We show that the Born's rule is incompatible with Lorentz symmetry of the Square Root Klein-Gordon equation (SRKG equation). It has been demonstrated that the Born rule must be modified in relativistic regime if one wishes to keep the SRKG equation as the correct equation for describing quantum behavior. 
Mohammad Javad Kazemi, Mohammad H.Barati, Jafar Khodagholizadeh and   Alireza Babazadeh
quant-ph