Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Chaos and Brane-worlds   The early time behaviour of brane-world models is analysed in the presence of
anisotropic stresses. It is shown that that the initial singularity cannot be
isotropic, unless there is also an isotropic fluid stiffer than radiation
present. Also, a magnetic Bianchi type I brane-world is analysed in detail. It
is known that the Einstein equations for the magnetic Bianchi type I models are
in general oscillatory and are believed to be chaotic, but in the brane-world
model this chaotic behaviour does not seem to be possible.

17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas