Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Photon Propagator in Light-Shell Gauge   We derive the photon propagator in light-shell gauge, which was first
introduced in the context of light-shell effective theory.

36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph