Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface links which are coverings over the standard torus   We introduce a new construction of a surface link in the 4-space. We
construct a surface link as a branched covering over the standard torus, which
we call a torus-covering link. We show that a certain torus-covering $T^2$-link
is equivalent to the split union of spun $T^2$-links and turned spun
$T^2$-links. We show that a certain torus-covering $T^2$-link has a
non-classical link group. We give a certain class of ribbon torus-covering
$T^2$-links. We present the quandle cocycle invariant of a certain
torus-covering $T^2$-link obtained from a classical braid, by using the quandle
cocycle invariants of the closure of the braid.

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The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org