I am looking for some information regarding the Heisenberg-Ivanenkov equation. I am only aware of the fact that it come in the unified theory created by Heisenberg and Pauli. How would Heisenberg's unified field equations (as presented in [*"Introduction to Unified Field Theory of Elementary Particles"*](http://dx.doi.org/10.1007/978-3-642-61742-3_62) by Heisenberg) be represented if gravity is incorporated? Would it result in a case similar to the [Heisenberg-Ivanenkov equation](http://www.google.com/search?as_q=Heisenberg+Ivanenko*), or am I just confused here?