Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The role of Hall diffusion in the magnetically threaded thin accretion
  discs   We study role of the Hall diffusion in the magnetic star-disc interaction. In
a simplified steady state configuration, the total torque is calculated in
terms of the fastness parameter and a new term because of the Hall diffusion.
We show the total torque reduces as the Hall term becomes more significant.
Also, the critical fastness parameter (at which the total torque is zero)
reduces because of the Hall diffusion.

13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
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: nlin