Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Innermost stable circular orbits around magnetized rotating massive
  stars   In 1998, Shibata and Sasaki [Phys. Rev. D 58, 104011 (1998)] presented an
approximate analytical formula for the radius of the innermost stable circular
orbit (ISCO) of a neutral test particle around a massive, rotating and deformed
source. In the present paper, we generalize their expression by including the
magnetic dipole moment. We show that our approximate analytical formulas are
accurate enough by comparing them with the six-parametric exact solution
calculated by Pach\'on et. al. [Phys. Rev. D 73, 104038 (2006)] along with the
numerical data presented by Berti and Stergioulas [MNRAS 350, 1416 (2004)] for
realistic neutron stars. As a main result, we find that in general, the radius
at ISCO exhibits a decreasing behavior with increasing magnetic field. However,
for magnetic fields below 100GT the variation of the radius at ISCO is
negligible and hence the non-magnetized approximate expression can be used. In
addition, we derive approximate analytical formulas for angular velocity,
energy and angular momentum of the test particle at ISCO.

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The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: stat
4
The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph