Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: PT-Symmetry Quantum Electrodynamics--PTQED   The construction of $\mathcal{PT}$-symmetric quantum electrodynamics is
reviewed. In particular, the massless version of the theory in 1+1 dimensions
(the Schwinger model) is solved. Difficulties with unitarity of the $S$-matrix
are discussed.

28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
2
The categories of this paper are: math
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph