Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exterior differential systems and billiards   I describe work in progress with Baryshnikov and Zharnitsky on periodic
billiard orbits that leads one to an exterior differential system (EDS). I then
give a brief introduction to EDS illustrated by several examples.

31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph