Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Onsager Symmetry Relation and the Time Inversion Invariance of the
  Entropy Production   Starting from the entropy production being invariant under time reversal, one
can (i) easily proof, and understand, many aspects of the linear Onsager
relations and (ii) deduce the result that all quadratic Onsager coefficients
for hydrodynamic fluxes vanish.

10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics