Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Isolated Electrostatic Structures Observed Throughout the Cluster Orbit:
  Relationship to Magnetic Field Strength   Isolated electrostatic structures are observed throughout much of the 4 Re by
19.6 Re Cluster orbit. These structures are observed in the Wideband plasma
wave instrument's waveform data as bipolar and tripolar pulses. These
structures are observed at all of the boundary layers, in the solar wind and
magnetosheath, and along auroral field lines at 4.5-6.5 Re. Using the Wideband
waveform data from the various Cluster spacecraft we have carried out a survey
of the amplitudes and time durations of these structures and how these
quantities vary with the local magnetic field strength. Such a survey has not
been carried out before, and it reveals certain characteristics of solitary
structures in a finite magnetic field, a topic still inadequately addressed by
theories. We find that there is a broad range of electric field amplitudes at
any specific magnetic field strength, and there is a general trend for the
electric field amplitudes to increase as the strength of the magnetic field
increases over a range of 5 to 500 nT. We provide a possible explanation for
this trend that releates to the structures being Bernstein-Greene-Kruskal mode
solitary waves. There is no corresponding dependence of the duration of the
structures on the magnetic field strength, although a plot of these two
quantities reveals the unexpected result that with the exception of the
magnetosheath, all of the time durations for all of the other regions are
comparable, wheras the magnetosheath time durations clearly are in a different
category of much smaller time duration. We speculate that this implies the
structures are much smaller in size.

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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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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: ao-sci
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The categories of this paper are: math
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The categories of this paper are: math-ph
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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: hep-th