Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Fundamental Group of a Spatial Section Represented by a Topspin
  Network   We present an algorithm which determines the fundamental group of a spatial
section using topspin networks. Tracking the topology of the spatial section is
a unique feature of this approach, which is not possible in standard Loop
Quantum Gravity. This leads to an example of spatial topology change in a
smooth 4-manifold represented by a topspin foam.

8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas