Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Second quantization method in the presence of bound states of particles   We develop an approximate second quantization method for describing the
many-particle systems in the presence of bound states of particles at low
energies (the kinetic energy of particles is small in comparison to the binding
energy of compound particles). In this approximation the compound and
elementary particles are considered on an equal basis. This means that creation
and annihilation operators of compound particles can be introduced. The
Hamiltonians, which specify the interactions between compound and elementary
particles and between compound particles themselves are found in terms of the
interaction amplitudes for elementary particles. The nonrelativistic quantum
electrodynamics is developed for systems containing both elementary and
compound particles. Some applications of this theory are considered.

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The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys