Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Temporal boundaries in electromagnetic materials   Temporally modulated optical media are important in both abstract and applied
applications, such as spacetime transformation optics, relativistic
laser-plasma interactions, and dynamic metamaterials. Here we investigate the
behaviour of temporal boundaries, and show that traditional approaches that
assume constant dielectric properties, with loss incorporated as an imaginary
part, necessarily lead to unphysical solutions. Further, although physically
reasonable predictions can be recovered with a narrowband approximation, we
show that appropriate models should use materials with a temporal response and
dispersive behaviour.

29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat