Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The role of the time delay in the reflection and transmission of
  ultrashort electromagnetic pulses on a system of parallel current sheets   The reflection and transmission of a few-cycle laser pulse impinging on two
parallel thin metal layers have been analyzed. The two layers, with a thickness
much smaller than the skin depth of the incoming radiation field, are
represented by current sheets embedded in three dielectrics, all with different
index of refraction. The dynamics of the surface currents and the scattered
radiation field are described by the coupled system of Maxwell-Lorentz
equations. When applying the plane wave modeling assumptions, these reduce to a
hybrid system of two delay differential equations for the electron motion in
the layers and a recurrence relation for the scattered field. The solution is
given as the limit of a singularly perturbed system and the effects of the time
delay on the dynamics is analyzed.

19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph