Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On invertible 2-dimensional framed and $r$-spin topological field
  theories   We classify invertible 2-dimensional framed and $r$-spin topological field
theories by computing the homotopy groups and the $k$-invariant of the
corresponding bordism categories. By a recent result of Kreck, Stolz and
Teichner the first homotopy groups are given by the so called SKK groups. We
compute them explicitly using the combinatorial model of framed and $r$-spin
surfaces of Novak, Runkel and the author.

15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
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The categories of this paper are: q-fin
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci