Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A nonrelativistic quantum field theory with point interactions in three
  dimensions   We construct a Hamiltonian for a quantum-mechanical model of nonrelativistic
particles in three dimensions interacting via the creation and annihilation of
a second type of nonrelativistic particles, which are bosons. The interaction
between the two types of particles is a point interaction concentrated on the
points in configuration space where the positions of two different particles
coincide. We define the operator, and its domain of self-adjointness, in terms
of co-dimension-three boundary conditions on the set of collision
configurations relating sectors with different numbers of particles.

15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th