Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-Homogeneous Backward-Wave Plasmonic Structures: Theory and
  Accurate Simulation   Backward waves and negative refraction are shown to exist in plasmonic
crystals whose lattice cell size is a very small fraction of the vacuum
wavelength (less than 1/40th in an illustrative example). Such
``quasi-homogeneity'' is important, in particular, for high-resolution imaging.
Real and complex Bloch bands are computed using the recently developed
finite-difference calculus of ``Flexible Local Approximation MEthods'' (FLAME)
that produces linear eigenproblems, as opposed to quadratic or nonlinear ones
typical for other techniques. FLAME dramatically improves the accuracy by
incorporating local analytical approximations of the solution into the
numerical scheme.

21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat