Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Groundstate splitting around rotating mini Blackholes   In this letter we present the result of a spin-dependent groundstate-energy
calculation for fermionic boundstates in the spacetime around a rotating
blackhole. Using a slow rotation approximation and a minimax variational
approach we find boundstate energies of 0 to 5 percent of the fermions
flatspace restmass. The groundstate displays a spin-dependent splitting with an
energy difference of about 10 percent of the binding energy. For a dilute gas
of primordial mini blackholes with gravitationally bound electrons spin-flip
transitions could possibly give rise to observable signatures in the observed
soft X-ray spectrum for sources at cosmological distances.

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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: eess
3
The categories of this paper are: physics
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: hep-th
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The categories of this paper are: math
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The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con