Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Premetric approach in gravity and electrodynamics   The basics of the premetric approach are discussed, including the essential
details of the formalism and some of its beautiful consequences. We demonstrate
how the classical electrodynamics can be developed without a metric in a quite
straightforward way: Maxwell's equations, together with the general response
law for material media, admit a consistent premetric formulation. Furthermore,
we show that in relativistic theories of gravity, the premetric program leads
to a better understanding of the interdependence between topological, affine,
and metric concepts.

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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: q-alg