Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evaluation of the two-photon exchange diagrams for the $(1s)^2 2p_{3/2}$
  electron configuration in Li-like ions   We present ab initio calculations of the complete gauge-invariant set of
two-photon exchange graphs for the $(1s)^2 2p_{3/2}$ electron configuration in
Li-like ions. These calculations are an important step towards the precise
theoretical determination of the $2p_{3/2}$-$2s$ transition energy in the
framework of QED.

21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an