Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermodynamic Properties of the Discommensuration Point for
  Incommensurate Structures: A "Third-Order" Phase Transition   The consequences of the opening of a phason gap in incommensurate systems are
studied on a simple model, the discrete frustrated $\phi^4$-model. Analytical
considerations and numerical results show that there is a very weak phase
transition that can be characterized as third order.

16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int