Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Of NBOs and kHz QPOs: a low-frequency modulation in resonant
  oscillations of relativistic accretion disks   The origin of quasi periodic modulations of flux in the kilohertz range (kHz
QPOs), observed in low-mass X-ray binaries, is usually assumed to be physically
distinct from that of the ``normal branch oscillations'' (NBOs) in the
Z-sources. We show that a low-frequency modulation of the kHz QPOs is a natural
consequence of the non-linear relativistic resonance suggested previously to
explain the properties of the high-frequency twin peaks. The theoretical
results discussed here are reminiscent of the 6 Hz variations of frequency and
amplitude of the kHz QPOs reported by Yu, van der Klis and Jonker (2001).

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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
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The categories of this paper are: q-alg
3
The categories of this paper are: physics
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The categories of this paper are: eess
1
The categories of this paper are: cs
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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: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con