Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self-Adjoint Extensions of the Dirac Hamiltonian with a delta-Sphere
  Interaction   The purpose of this paper is to make an explicit construction of specific
self-adjoint extensions of the Dirac Hamiltonian in the presence of a
$\delta$-sphere interaction of finite radius. The exact resolvent kernel of the
free Dirac operator is given. This specifies related results that have recently
appeared in the literature.

35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol