Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A traversable wormhole   The paper has been withdrawn by the author, due to a fatal error. A horse
stumbles that has four legs.

7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
3
The categories of this paper are: physics
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph