Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Ambarzumyan's theorem for the Quasi-periodic Problem   We obtain the classical Ambarzumyan's theorem for the Sturm-Liouville
operators $L_{t}(q)$ with $q\in L^{1}[0,1]$ and quasi-periodic boundary
conditions, $t\in [0,2\pi)$, when there is not any additional condition on the
potential $q$.

6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat