Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase Transition of RN-AdS Black Hole with Fixed Electric Charge and
  Topological Charge   Phase transition of RN-AdS black hole is investigated from a new perspective.
Not only the cosmological constant is treated as pressure, but also the spatial
curvature of black hole is treated as topological charge. We obtain the
extended thermodynamic first law from which the mass is naturally viewed as
enthalpy instead of energy. In canonical ensemble with fixed topological charge
and electric charge, interesting van der Waals system's oscillatory behavior in
$T-S$, $P-V$ graphes and swallow tail behavior in $G-T$, $G-P$ graphes are
observed. By applying the Maxwell equal area law and by analysing the gibbs
free energy, we obtain analytical phase transition coexistence curves ($T-P$)
which are consistent with each other.

0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat