Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self-adjointness of the two-dimensional massless Dirac Hamiltonian and
  vacuum polarization effects in the background of a singular magnetic vortex   A massless spinor field is quantized in the background of a singular static
magnetic vortex in 2+1-dimensional space-time. The method of self-adjoint
extensions is employed to define the most general set of physically acceptable
boundary conditions at the location of the vortex. Under these conditions, all
effects of polarization of the massless fermionic vacuum in the vortex
background are determined. Absence of anomaly is demonstrated, and patterns of
both parity and chiral symmetry breaking are discussed.

37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph