Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterization of solar-cycle induced frequency shift of medium- and
  high-degree acoustic modes   Although it is well known that the solar acoustic mode frequency increases as
the solar activity increases, the mechanism behind it is still unknown. Mode
frequencies with 20 < l < 900 obtained by applying spherical harmonic
decomposition to MDI full-disk observations were used. First, the dependence of
solar acoustic mode frequency with solar activity was examined and evidence of
a quadratic relation was found indicating a saturation effect at high solar
activity. Then, the frequency dependence of frequency differences between the
activity minimum and maximum was analyzed. The frequency shift scaled by the
normalized mode inertia follows a simple power law where the exponent for the p
modes decreases by 37% for modes with frequency larger than 2.5 mHz.

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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
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The categories of this paper are: econ
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The categories of this paper are: adap-org
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The categories of this paper are: hep-th
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an