Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Freezing of the optical--branch energy in a diatomic FPU chain   We study the exchange of energy between the modes of the optical branch and
those of the acoustic one in a diatomic chain of particles, with masses $m_1$
and $m_2$. We prove that, at small temperature and provided $m_1\gg m_2$, for
the majority of the initial data the energy of each branch is approximately
constant for times of order $\beta^{S/2}$, where $S=\lfloor
\sqrt{m_1/m_2}/2\rfloor$ and $\beta$ is the inverse temperature. The result is
uniform in the thermodynamic limit.

26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn