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subshift
  • Member for 15 years, 2 months
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Spectrum of primitive nonnegative integer matrices
Right now the best I can do is to enumerate all the matrices (using the trace constraint) and test them one by one... Can anyone think of a less stupid approach?
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Spectrum of primitive nonnegative integer matrices
Gerry, I haven't looked at it for hours but it doesn't seem to be obvious even for $2\times2$ matrices.
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Spectrum of primitive nonnegative integer matrices
David, unfortunately I would like to avoid the additional zero eigenvalues. Is this question open even without the primitivity assumption? Thanks for the very interesting articles!
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What are the most attractive Turing undecidable problems in mathematics?
Note the recent preprint arxiv.org/abs/1312.6700 which improves these results. Undecidability now holds for five 3*3 matrices or two 15*15 matrices.
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