Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum mechanics as an approximation of statistical mechanics for
  classical fields   We show that, in spite of a rather common opinion, quantum mechanics can be
represented as an approximation of classical statistical mechanics. The
approximation under consideration is based on the ordinary Taylor expansion of
physical variables. The quantum contribution is given by the term of the second
order. To escape technical difficulties, we start with the finite dimensional
quantum mechanics. In our approach quantum mechanics is an approximative
theory. It predicts statistical averages only with some precision. In
principle, there might be found deviations of averages calculated within the
quantum formalism from experimental averages (which are supposed to be equal to
classical averages given by our model).

2
The categories of this paper are: math
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin