Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The membrane paradigm for a dynamic wormhole   A classical membrane model is developed for a dynamic wormhole. Its throat
expands hyperbolically with an acceleration proportional to the surface energy
density $\sigma$. The model leads to a negative bulk viscosity coefficient
$\zeta = - 1/6 \pi$ on the throat, expressing the instability against
perturbations (expansions or contractions).

19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio