Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bifurcations of Liouville Tori in Elliptical Billiards   A detailed description of topology of integrable billiard systems is given.
For elliptical billiards and geodesic billiards on ellipsoid, the corresponding
Fomenko graphs are constructed.

31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin