Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On codimension two embeddings up to link-homotopy   We consider knotted annuli in 4-space, called 2-string-links, which are
knotted surfaces in codimension two that are naturally related, via closure
operations, to both 2-links and 2-torus links. We classify 2-string-links up to
link-homotopy by means of a 4-dimensional version of Milnor invariants. The key
to our proof is that any 2-string link is link-homotopic to a ribbon one; this
allows to use the homotopy classification obtained in the ribbon case by P.
Bellingeri and the authors. Along the way, we give a Roseman-type result for
immersed surfaces in 4-space. We also discuss the case of ribbon k-string
links, for $k\geq 3$.

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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: nlin
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The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
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The categories of this paper are: funct-an
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The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph