Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometric thermodynamics: black holes and the meaning of the scalar
  curvature   In this paper we show that the vanishing of the scalar curvature of
Ruppeiner-like metrics does not characterize the ideal gas. Furthermore, we
claim through an example that flatness is not a sufficient condition to
establish the absence of interactions in the underlying microscopic model of a
thermodynamic system, which poses a limitation on the usefulness of Ruppeiner's
metric and conjecture. Finally, we address the problem of the choice of
coordinates in black hole thermodynamics. We propose an alternative energy
representation for Kerr-Newman black holes that mimics fully Weinhold's
approach. The corresponding Ruppeiner's metrics become degenerate only at
absolute zero and have non-vanishing scalar curvatures.

33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin