Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ermakov approach for Q=0 empty FRW minisuperspace oscillators   The Wheeler-DeWitt equation for empty FRW minisuperspace universes of
Hartle-Hawking factor ordering parameter Q=0 is mapped onto the dynamics of a
unit mass classical oscillator. The latter is studied by the classical Ermakov
invariant method. Angle quantities are presented in the same context

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The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
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The categories of this paper are: econ
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: astro-ph