Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gapped boundaries and string-like excitations in (3+1)d gauge models of
  topological phases   We study lattice Hamiltonian realisations of (3+1)d Dijkgraaf-Witten theory
with gapped boundaries. In addition to the bulk loop-like excitations, the
Hamiltonian yields bulk dyonic string-like excitations that terminate at gapped
boundaries. Using a tube algebra approach, we classify such excitations and
derive the corresponding representation theory. Via a dimensional reduction
argument, we relate this tube algebra to that describing (2+1)d boundary
point-like excitations at interfaces between two gapped boundaries. Such
point-like excitations are well known to be encoded into a bicategory of module
categories over the input fusion category. Exploiting this correspondence, we
define a bicategory that encodes the string-like excitations ending at gapped
boundaries, showing that it is a sub-bicategory of the centre of the input
bicategory of group-graded 2-vector spaces. In the process, we explain how
gapped boundaries in (3+1)d can be labelled by so-called pseudo-algebra objects
over this input bicategory.

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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
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The categories of this paper are: stat
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn