Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Traversable intra-Universe wormholes and timeholes in General
  Relativity: two new solutions   Using thin shell formalism we construct two solutions of intra-universe
wormholes. The first model is a cosmological analog of the Aichelburg-Schein
timehole, while another one is an intra-universe form of the Bronnikov-Ellis
solution.

0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
1
The categories of this paper are: cs
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph