Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The gravitational magnetoelectric effect   Electromagnetism in spacetime can be treated in terms of an analogue linear
dielectric medium. In this paper, we discuss the gravitational analogue of the
linear magnetoelectric effect, which can be found in multiferroic materials.
While this is known to occur for metrics with non-zero mixed components, we
show how it depends on the choice of spatial formalism for the electromagnetic
fields, including in differences in tensor weight, and also on the choice of
coordinate chart. This is illustrated for Langevin-Minkowski, four charts of
Schwarzschild spacetime, and two charts of pp gravitational waves.

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The categories of this paper are: solv-int
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The categories of this paper are: physics
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The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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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: stat
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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol