Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Calculating spatiotemporally modulated surfaces: a dynamical
  differential formalism   Electromagnetic waves in a system with a space and time dependent boundary
experience both diffraction and Doppler-like frequency conversion. In order to
analyse such situations, conventional methods call for either the eigenmodes or
the dyadic Green's function in space and time dependent media. Here, we propose
a dynamical differential method which does not require either of them. Our
method utilises a dynamical coordinate transformation in order to simplify the
calculation of the optical response of the space and time dependent system. We
reveal that the diffraction symmetry is broken in the presence of
traveling-wave type spatiotemporal modulation.

11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin