Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dirac equation for quasi-particles in graphene in an external
  electromagnetic field and chiral anomaly   There is evidence for existence of massless Dirac quasi-particles in
graphene, which satisfy Dirac equation in (1+2) dimensions near the so called
Dirac points which lie at the corners at the graphene's brilluoin zone. It is
shown that parity operator in (1+2) dimensions play an interesting role and can
be used for defining conserved chiral currents [there is no gamma^5 in (1+2)
dimensions]. It is shown that the "anomalous" current induced by an external
gauge field can be related to the anomalous divergence of an axial vector
current which arises due to quantum radiative corrections provided by
triangular loop Feynman diagrams in analogy with the corresponding axial
anomaly in (1+3) dimensions.

12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat