Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effective Lagrangian of Thermal QED with External Magnetic Field and the
  Static Limit of the Polarization Operator   A low-temperature expansion of QED one-loop effective Lagrangian valid for a
wide range of parameters is presented in a form of finite sums of elementary
functions. Starting from the effective action components of the one-loop
polarization operator responsible for Hall conductivity and Debye screening are
obtained. It is shown that in a strong background magnetic field the Debye
radius depends on spatial direction.

3
The categories of this paper are: physics
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The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
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The categories of this paper are: hep-ex
28
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
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
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The categories of this paper are: astro-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: math