Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy-momentum tensor for the electromagnetic field in a dispersive
  medium as an application of Noether theorem   On the basis of a non-local Lagrangian for Maxwell equations in a dispersive
medium, the energy-momentum tensor of the field is derived. We obtain the Field
equations through variational methods and an extension of Noether theorem for a
non-local Lagrangian is obtained as well. The electromagnetic energy-momentum
tensor obtained in the general context is then specialized to the case of a
field with slowly varying amplitude on a rapidly oscillating carrier.

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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: econ
7
The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
2
The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an