Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quaternionic matrices: Unitary similarity, simultaneous
  triangularization and some trace identities   We construct six unitary trace invariants for 2 by 2 quaternionic matrices
which separate the unitary similarity classes of such matrices, and show that
this set is minimal. We prove two quaternionic versions of a well known
characterization of triangularizable subalgebras of matrix algebras over an
algebraically closed field. Finally we consider the problem of describing the
semi-algebraic set of pairs (X,Y) of quaternionic n by n matrices which are
simultaneously triangularizable. Even the case n=2, which we analyze in more
detail, remains unsolved.

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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
31
The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio