Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hyperfine splitting in noncommutative spaces   We study the hyperfine splitting in the framework of the noncommutative
quantum mechanics (NCQM) developed in the literature. The results show
deviations from the usual quantum mechanics. We show that the energy difference
between two excited F = I + 1/2 and the ground F = I - 1/2 states in a
noncommutative space (NCS) is bigger than the one in the commutative case, so
the radiation wavelength in NCSs must be shorter than the radiation wavelength
in commutative spaces. We also find an upper bound for the noncommutativity
parameter.

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The categories of this paper are: dg-ga
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The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci