Photon as the zero-mass limit of DKP field

Abstract

It is shown that Maxwell's equations can be obtained as the zero-mass limit of the Duffin-Kemmer-Petiau equation for the massive spin-one particle with appropriate identification of the components of the DKP spinor with electromagnetic field strengths and potentials. The electromagnetic Lagrangian also follows from the DKP Lagrangian in the same limit.