Application of Lie algebroid structures to unification of Einstein and   yang-mills field equations
  Yang-mills field equations describe new forces in the context of Lie groups and principle bundles. It is of interest to know if the new forces and gravitation can be described in the context of algebroids. This work was intended as an attempt to answer last question. The basic idea is to construct Einstein field equation in an algebroid bundle associated to space-time manifold. This equation contains Einstein and yang-mills field equations simultaneously. Also this equation yields a new equation that can have interesting experimental results. 
Naiereh Elyasi and Nasser Boroojerdian
gr-qc