Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gravitational Wave Electrodynamics   We derive Maxwell equations for electric and magnetic fields in curved
spacetime from first principles. We show that the latter system enjoys an SO(2)
duality symmetry, contrary to the results of previous works. We find that in a
detector with static background magnetic or electric field, the weak gravity
effects are analogous to the effects from a medium composed of both
electrically and magnetically charged particles. We show that generation of
electromagnetic radiation by gravitational waves in an external magnetic field
is four times more efficient than previously believed. We discuss differences
between axion and gravitational wave electrodynamics.

23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph