Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Monopole and dipole layers in curved spacetimes: formalism and examples   The discontinuities of electromagnetic test fields generated by general
layers of electric and magnetic monopoles and dipoles are investigated in
general curved spacetimes. The equivalence of electric currents and magnetic
dipoles is discussed. The results are used to describe exact "Schwarzschild
disk" solutions endowed with such sources. The resulting distributions of
charge and dipole densities on the disks are corroborated using the membrane
paradigm.

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The categories of this paper are: acc-phys
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ