Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The density of a fluid on a curved surface   We discuss the property of the number density of a fluid of particles living
in a curved surface without boundaries to be constant in the thermodynamic
limit. In particular we find a sufficient condition for the density to be
constant along the Killing vector field generating a given isometry of the
surface and the relevant necessary condition. We reinterpret the effect of a
curvature on the fluid in a physical way as responsible of an external "force"
acting on the particles.

7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg