Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A thermodynamic approach to the T-models   The perfect fluid solutions admitting a group G$_3$ of isometries acting on
orbits S$_2$ whose curvature has a gradient which is tangent to the fluid flow
(T-models) are studied from a thermodynamic approach. All the admissible
thermodynamic schemes are obtained, and the solutions compatible with the
generic ideal gas equation of state are studied in detail. The possible
physical interpretation of some previously known T-models is also analyzed.

8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th