Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Compression induced folding of a sheet: an integrable system   The apparently intractable shape of a fold in a compressed elastic film lying
on a fluid substrate is found to have an exact solution. Such systems buckle at
a nonzero wavevector set by the bending stiffness of the film and the weight of
the substrate fluid. Our solution describes the entire progression from a
weakly displaced sinusoidal buckling to a single large fold that contacts
itself. The pressure decrease is exactly quadratic in the lateral displacement.
We identify a complex wavevector whose magnitude remains invariant with
compression.

23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math