Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The inner disk radius in the propeller phase and accretion-propeller
  transition of neutron stars   We have investigated the critical conditions required for a steady propeller
effect for magnetized neutron stars with optically thick, geometrically thin
accretion disks. We have shown through simple analytical calculations that a
steady-state propeller mechanism cannot be sustained at an inner disk radius
where the viscous and magnetic stresses are balanced. The radius calculated by
equating these stresses is usually found to be close to the conventional Alfven
radius for spherical accretion, r_A. Our results show that: (1) a steady
propeller phase can be established with a maximum inner disk radius that is at
least \sim 15 times smaller than r_A depending on the mass-flow rate of the
disk, rotational period and strength of the magnetic dipole field of the star,
(2) the critical accretion rate corresponding to the accretion-propeller
transition is orders of magnitude lower than the rate estimated by equating r_A
to the co-rotation radius. Our results are consistent with the properties of
the transitional millisecond pulsars which show transitions between the
accretion powered X-ray pulsar and the rotational powered radio pulsar states.

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The categories of this paper are: nlin
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The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-th