Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum equivalent of the Bertrand's theorem   A procedure for constructing bound state potentials is given. We show that,
under the natural conditions imposed on a radial eigenvalue problem, the only
special cases of the general central potential, which are exactly solvable and
have infinite number of energy eigenvalues, are the Coulomb and harmonic
oscillator potentials.

15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph