Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Macroscopic Black Holes, Microscopic Black Holes and Noncommutative
  Membrane   We study the stretched membrane of a black hole as consisting of a perfect
fluid. We find that the pressure of this fluid is negative and the specific
heat is negative too. A surprising result is that if we are to assume the fluid
be composed of some quanta, then the dispersion relation of the fundamental
quantum is $E=m^2/k$, with $m$ at the scale of the Planck mass. There are two
possible interpretation of this dispersion relation, one is the noncommutative
spacetime on the stretched membrane, another is that the fundamental quantum is
microscopic black holes.

3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
1
The categories of this paper are: cs