Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Consequences of a condensed matter realization of Lorentz violating QED
  in Weyl semi-metals   In Lorentz violating quantum electrodynamics (QED) it is known that a
radiatively induced Chern-Simons term appears in the effective action for the
gauge field, which is finite but undetermined. This ambiguity is shown to be
absent in a condensed matter realization of such a theory in Weyl semi-metals
due to the existence of a full microscopic model from which this effective
theory emerges. Physically observable consequences such as birefringence are
also discussed in this scenario.

11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg