Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sum rule for the optical Hall angle   We consider the optical Hall conductivity of a general electronic medium and
prove that the optical Hall angle obeys a new sum rule. This sum rule governs
the response of an electronic fluid to a Lorentz electric field and can thought
of as the transverse counterpart to the f-sum rule in optical conductivity. The
physical meaning of this sum rule is discussed, giving a number of examples of
its application to a variety of of electronic media.

5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
2
The categories of this paper are: math
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics