Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Trajectories in Logarithmic Potentials   Trajectories in logarithmic potentials are investigated by taking as example
the motion of an electron within a cylindrical capacitor. The solution of the
equation of motion in plane polar coordinates, (r,{\phi}) is attained by
forming a series expansion of r and of 1/r as a function of {\phi}. The terms
of the series contain polynomials, the recurrence relation of which is given,
together with some further characteristics. By the comparison-theorem of
infinite series, the convergence of the solution is demonstraded. The simplest
trajectories in logarithmic potentials are represented by rosette type orbits
with a period of 4{\pi}/3, and by circular paths.

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The categories of this paper are: adap-org
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys