Are differential forms related to Azumaya algebras? While studying vector bundle valued differential forms, $\Omega^{\bullet}(M, E)$, or $\Omega^{\bullet}(M, \mathrm{End}(E))$ if that helps this discussion, I've come across some work in Azumaya algebras.  Thinking of $\Omega$ as an $R$-module, taking values in a bundle, and reading about how Azumaya algebras can be thought of locally being a matrix algebra, in the right context, it seems there should be a connection between $\Omega$ and Azumaya algebras.  Can anyone point me in the right direction or tell me why this doesn't work? 
Question: Can we say that $\Omega^{\bullet}(M,E)$ is an Azumaya algebra?
 A: OK, I made a real hash of this the first time, so let me straighten this all out:
Azumaya algebras (at least as I understand them) are algebras which are locally isomorphic to $\mathrm{End}(E)$ for $E$ a vector bundle.  Note, I'm being a little vague here, since there are many contexts, many topologies, etc. where one might want to do this.  There's a general yoga for understanding such algebras: there's a coordinate atlas where they are trivial, so all you need to say is the trivialization on each patch, and what the transition functions are.  This is an element of Čech 1-cocycles for this cover for the sheaf $\mathrm{End}(E)^*$; you can easily work out that the isomorphic Azumaya algebras are those that come from 2-cocyles via the boundary map (you conjugate the transitions by the 2-cocycle).  
So, the first sheaf homology of $\mathrm{End}(E)^*$ controls the Azumaya algebras; that's all I was trying to say; since it's a multiplicative sheaf, I think interpreting it as deRham cohomology will be trickier than I first imagined.
