ABSTRACT
This chapter provides a description of some of the main approaches
suitable for modeling enhanced electromagnetic fields in plasmonic
nanostructures, ranging from the quasi-static approximation to
the exact description in terms of higher order multipole field
expansions and the consideration of nonlocal and quantum effects.
The strengths and limitations of each method will be discussed in
terms of efficiency, accuracy, and applicability to nanoplasmonic
systems of interest.