I was wondering if anyone could provide good reference texts for studying the Dirichlet to Neumann map of an elliptic operator?
Ideally it would be one of the later chapters of an introductory/general theory of elliptic operators. In particular I am not looking for anything too advanced, just a gentle foray into the topic.
Something like Evans PDE would be perfect -- I say like as Evans does not seem to take up the topic in that book.
thanks!