Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the nature of kinetic electrostatic electron nonlinear (KEEN) waves   An analytical theory is proposed for the kinetic electrostatic electron
nonlinear (KEEN) waves originally found in simulations by Afeyan et al
[arXiv:1210.8105]. We suggest that KEEN waves represent saturated states of the
negative mass instability (NMI) reported recently by Dodin et al [Phys. Rev.
Lett. 110, 215006 (2013)]. Due to the NMI, trapped electrons form
macroparticles that produce field oscillations at harmonics of the bounce
frequency. At large enough amplitudes, these harmonics can phase-lock to the
main wave and form stable nonlinear dissipationless structures that are
nonstationary but otherwise similar to Bernstein-Greene-Kruskal modes. The
theory explains why the formation of KEEN modes is sensitive to the excitation
scenario and yields estimates that agree with the numerical results of Afeyan
et al. A new type of KEEN wave may be possible at even larger amplitudes of the
driving field than those used in simulations so far.

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The categories of this paper are: cond-mat
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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The categories of this paper are: hep-lat
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: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: hep-ph
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The categories of this paper are: q-bio
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The categories of this paper are: math
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The categories of this paper are: patt-sol