Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resonant Excitation of Disk Oscillations in Deformed Disks VI: Stability
  Criterion Revisited   We re-examine excitation of a set of disk oscillations in a deformed disk by
a resonant process. We assume that the disk is deformed from an axisymmetric
steady state by an oscillatory deformation with frequency $\omega_{\rm D}$ and
azimuthal wavenumber $m_{\rm D}$. Then, we consider two normal mode
oscillations with a set of frequencies and azimuthal wavenumber being
($\omega_1$, $m_1$) and ($\omega_2$, $m_2$) and satisfying the resonant
conditions ($\omega_1+\omega_2+\omega_{\rm D}=0$ and $m_1+m_2+m_{\rm D}=0$).
These oscillations are resonantly excited if $(E_1/\omega_1)(E_2/\omega_2)>0$,
where $E_1$ and $E_2$ are wave energies of the above two oscillations, when the
deformation is maintained by external forces or has a large amplitude compared
with the oscillations. This instability condition is rather general as long as
unperturbed density and pressure vanish on the surface of the system.
Possibility of application to superhump and negative superhump in superoutburst
state of dwarf novae are briefly discussed.

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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: nlin
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The categories of this paper are: physics
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn