Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Upper limit on the number of bound states of the spinless Salpeter
  equation   We obtain, using the Birman-Schwinger method, upper limits on the total
number of bound states and on the number of $\ell$-wave bound states of the
semirelativistic spinless Salpeter equation. We also obtain a simple condition,
in the ultrarelativistic case ($m=0$), for the existence of at least one
$\ell$-wave bound states: $C(\ell,p/(p-1))$ $\int_0^{\infty}dr r^{p-1}
|V^-(r)|^p\ge 1$, where $C(\ell,p/(p-1))$ is a known function of $\ell$ and
$p>1$.

37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph