Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Borcherds Products for U(1,1)   The Borcherds lift for indefinite unitary groups, previously constructed by
the author, is examined here in greater detail for the special case of the
group U(1,1). The inputs for the lifting in this case are weakly holomorphic
modular forms of weight zero, which are lifted to meromorphic modular forms on
the usual complex upper half plane transforming under an arithmetic subgroup of
U(1,1). In this setting, we can completely describe the Weyl-chambers involved
and explicitly calculate the attached Weyl-vectors, for a family of input
functions with principle part $q^{-n}$. Since these are a basis for the input
space, we obtain similarly explicit results for arbitrary input functions. The
Heegner divisors in this case consist of CM-points, the CM-order of which is
also determined.

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The categories of this paper are: quant-ph
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: physics
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: nlin
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an