Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Casimir energy of massive MIT fermions in a Bohm-Aharonov background   We study the effect of a background flux string on the vacuum energy of
massive Dirac fermions in 2+1 dimensions confined to a finite spatial region
through MIT boundary conditions. We treat two admissible self-adjoint
extensions of the Hamiltonian and compare the results. In particular, for one
of these extensions, the Casimir energy turns out to be discontinuous at
integer values of the flux.

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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: nlin
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The categories of this paper are: mtrl-th
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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
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The categories of this paper are: econ
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The categories of this paper are: nucl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph