How to write a Ph.D. thesis Introduction chapter?
My thesis, which does happen to be in the area you are writing about, took a somewhat different approach for the introductory chapter:


Motivations—why is this particular problem important
Related efforts—in what context was the work done
A short summary of the main development of the thesis (without a formal hypothesis statement)
An outline of the remainder of the thesis 


The following chapter, which was also an "introductory" chapter, but more of a "preliminaries" chapter, defines all the major concepts, tools, and ideas used in the remainder of the thesis (which were derived from my published papers, and therefore somewhat briefer than what is needed for a thesis).