Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sommerfeld's quantum condition of action and the spectra of
  Schwarzschild black hole   If the situation of quantum gravity nowadays is nearly the same as that of
the quantum mechanics in it's early time of Bohr and Sommerfeld, then a first
step study of the quantum gravity from Sommerfeld's quantum condition of action
might be helpful. In this short paper the spectra of Schwarzschild black
hole(SBH) in quasi-classical approach of quantum mechanics is given. We find
the quantum of area, the quantum of entropy and the Hawking evaporation will
cease as the black hole reaches its ground state.

28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys