Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetically Arrested Disk: An Energetically Efficient Accretion Flow   We consider an accretion flow model originally proposed by Bisnovatyi-Kogan &
Ruzmaikin (1974), which has been confirmed in recent 3D MHD simulations. In the
model, the accreting gas drags in a strong poloidal magnetic field to the
center such that the accumulated field disrupts the axisymmetric accretion flow
at a relatively large radius. Inside the disruption radius, the gas accretes as
discrete blobs or streams with a velocity much less than the free-fall
velocity. Almost the entire rest mass energy of the gas is released as heat,
radiation and mechanical/magnetic energy. Even for a non-rotating black hole,
the efficiency of converting mass to energy is of order 50% or higher. The
model is thus a practical analog of an idealized engine proposed by Geroch and
Bekenstein.

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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: hep-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an