Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On reduced twisted group C*-algebras that are simple and/or have a
  unique trace   We study the problem of determining when the reduced twisted group C*-algebra
associated with a discrete group G is simple and/or has a unique tracial state,
and present new sufficient conditions for this to hold. One of our main tools
is a combinatorial property, that we call the relative Kleppner condition,
which ensures that a quotient group G/H acts by freely acting automorphisms on
the twisted group von Neumann algebra associated to a normal subgroup H. We
apply our results to different types of groups, e.g. wreath products and
Baumslag-Solitar groups.

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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga