Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Class of solutions of the Wheeler-DeWitt equation in the
  Friedmann-Robertson-Walker universe   We show that the solutions of the Wheeler-DeWitt equation in a homogeneous
and isotropic universe are given by triconfluent Heun functions for the
spatially closed, flat, and open geometries of the Friedmann-Robertson-Walker
universe filled with different forms of energy. In a matter-dominated universe,
we find the polynomial solution and the energy density spectrum. In the cases
of radiation-dominated and vacuum universes, there are no polynomial solutions
as shown.

22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat