Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solutions of the Dirac Equation in a Magnetic Field and Intertwining
  Operators   The intertwining technique has been widely used to study the Schr\"odinger
equation and to generate new Hamiltonians with known spectra. This technique
can be adapted to find the bound states of certain Dirac Hamiltonians. In this
paper the system to be solved is a relativistic particle placed in a magnetic
field with cylindrical symmetry whose intensity decreases as the distance to
the symmetry axis grows and its field lines are parallel to the $x-y$ plane. It
will be shown that the Hamiltonian under study turns out to be shape invariant.

20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph