Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Isometric immersions of R^2 into R^4 and pertubation of Hopf tori   We produce a new general family of flat tori in R^4, the first one since
Bianchi's classical works in the 19th century. To construct these flat tori,
obtained via small perturbation of certain Hopf tori in S^3, we first present a
global description of all isometric immersions of R^2 into R^4 with flat normal
bundle.

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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an