Electromagnetic Field in Lyra Manifold: A First Order Approach
  We discuss the coupling of the electromagnetic field with a curved and torsioned Lyra manifold using the Duffin-Kemmer-Petiau theory. We will show how to obtain the equations of motion and energy-momentum and spin density tensors by means of the Schwinger Variational Principle. 
R. Casana, C. A. M. de Melo and B. M. Pimentel
gr-qc astro-ph.CO hep-th math-ph math.DG math.MP