Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constructing Combinatorial 4-Manifolds   Every closed oriented PL 4-manifold is a branched cover of the 4-sphere
branched over a PL-surface with finitely many singularities by Piergallini
[Topology 34(3):497-508, 1995]. This generalizes a long standing result by
Hilden and Montesinos to dimension four. Izmestiev and Joswig [Adv. Geom.
3(2):191-225, 2003] gave a combinatorial equivalent of the Hilden and
Montesinos result, constructing closed oriented combinatorial 3-manifolds as
simplicial branched covers of combinatorial 3-spheres. The construction of
Izmestiev and Joswig is generalized and applied to the result of Piergallini,
obtaining closed oriented combinatorial 4-manifolds as simplicial branched
covers of simplicial 4-spheres.

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The categories of this paper are: cs
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol