Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analogue of the Kubo Formula for Conductivity of Spatially Inhomogeneous
  Systems and Electric Fields   The average of densities of currents and charges, induced by a weak
electromagnetic field in spatially inhomogeneous are calculated at final
temperatures. The Kubo formula for a conductivity tensor is generalized for
spatially inhomogeneous systems and fields. The contributions containing
electric fields and derivative from fields on coordinates are allocated. The
Semiconductor quantum wells, wires and dots may be considered as spatially
inhomogeneous systems.

8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio