Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Approximate expressions for polar gap electric field of pulsars   We derive easy-to-handle approximations for the polar gap electric field due
to inertial frame dragging as derived by Harding & Muslimov 1998. A simple
formula valid for polar gap height comparable to the polar cap radius is
presented.

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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
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The categories of this paper are: eess
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
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The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th