Poincare group operators with 4-vector position

Abstract

We present a new set of massless Poincar\'e group operators Hermitian with respect to the $ 1 / r $ inner product space, which have quasi-plane wave energy-momentum eigenfunctions having velocity $ c $ along their axis of propagation. These are constructed by means of a unitary transformation from a known set of massless Poincar\'e group operators of helicity $ s = 0, \pm {1 \over 2}, \pm 1 ... $ The position vector $ {\bf r} $ is the space part of a null 4-vector.