Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Why Jefimenko equations ? (A comment on "Multipole radiation fields from
  the Jefimenko equation...", by R. de Melo e Souza et al, Am. J. Phys. 77 (1),
  67-72 (2009), arXiv:0812.4679)   In this comment, we discuss some features of the multipolar expansion of the
power radiated by a confined system of charges and currents, and the
possibility of generalization to a higher arbitrary order of the multipolar
expansion.

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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: funct-an
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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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: math
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The categories of this paper are: astro-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph