Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chaos in the Classical Analogue of the Hofstadter Problem   The behaviour of an electron in a potential that resembles that of a
bidimensional solid with a perpendicular magnetic field applied is studied from
a classical point of view. This problem presents the standard features of chaos
and some interesting new patterns. A new chaos indicator, called random walk
indicator, is presented to describe som of these new patterns

19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th