Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometry of Integral Binary Hermitian Forms   We generalize Conway's approach to integral binary quadratic forms on Q to
study integral binary hermitian forms on quadratic imaginary extensions of Q.
In Conway's case, an indefinite form that doesn't represent 0 determines a line
("river") in the spine T associated with SL(2,Z) in the hyperbolic plane. In
our generalization, such a form determines a plane ("ocean") in Mendoza's spine
associated with the corresponding Bianchi group SL(2,A) in hyperbolic 3-space.

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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: cs
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: econ
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The categories of this paper are: q-bio
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The categories of this paper are: physics