Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The geometry of bi-Perron numbers with real or unimodular Galois
  conjugates   Among all bi-Perron numbers, we characterise those all of whose Galois
conjugates are real or unimodular as the ones that admit a power which is the
stretch factor of a pseudo-Anosov homeomorphism arising from Thurston's
construction. This is in turn equivalent to admitting a power which is the
spectral radius of a bipartite Coxeter transformation.

18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: astro-ph
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The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
1
The categories of this paper are: cs
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The categories of this paper are: stat