Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Circle actions on simply connected 5--manifolds   The aim of this paper is to study compact 5--manifolds which admit fixed
point free circle actions. The first result implies that the torsion in the
second homology and the second Stiefel--Whitney class have to satisfy strong
restrictions. We then show that for simply connected 5--manifolds these
restrictions are necessary and sufficient.

29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio